Fluke 2680A Service Manual
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Fluke 2680A Service Manual

Data acquisition system/data logging system
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268XA
Data Acquisition System/Data Logging System
Service Manual
PN 1883791
November 2002
© 2002 Fluke Corporation. All rights reserved. Printed in USA
All product names are trademarks of their respective companies.

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Summary of Contents for Fluke 2680A

  • Page 1 ® 268XA Data Acquisition System/Data Logging System Service Manual PN 1883791 November 2002 © 2002 Fluke Corporation. All rights reserved. Printed in USA All product names are trademarks of their respective companies.
  • Page 2 Fluke authorized resellers shall extend this warranty on new and unused products to end-user customers only but have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is available only if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price.
  • Page 3 WCaution This is an IEC safety Class 1 product. Before using, the ground wire in the line cord or rear panel binding post must be connect to an earth ground for safety. Interference Information This equipment generates and uses radio frequency energy and if not installed and used in strict accordance with the manufacturer’s instructions, may cause interference to radio and television reception.
  • Page 4 The input is protected by a 4 ampere fuse internal to the device. This fuse should only be replaced by a qualified Fluke technician. GROUNDING THE DEVICE...
  • Page 5 Refer all question of proper device operation to qualified service personnel. DO NOT ATTEMPT TO SERVICE UNLESS YOU ARE A FLUKE QUALIFIED REPAIR TECHNICIAN To avoid personal injury or death, remove the AC power cord and all analog and digital connector modules before servicing the device.

  • Page 7: Table Of Contents

    Introduction ....................... 1-3 Block Diagrams ....................1-5 Specifications ....................1-7 2680A/2686A Combined Specifications............1-7 2680A/2686A General Specifications ............... 1-8 Real-Time Clock and Calendar ................. 1-9 Trigger In Specifications ................... 1-9 Trigger Out Specifications ................1-9 Master Alarm Output Specification..............1-10 Communication I/O ...................
  • Page 8 268XA Service Manual Theory of Operation................2-1 Introduction ....................... 2-3 Main Power Supply..................2-5 Secondary Supplies ..................2-5 Out-Guard Overview..................2-5 Microprocessor ..................2-6 FPGA ......................2-7 Other Bus Devices ..................2-8 Serial Devices ................... 2-9 Trigger In/Out, Master Alarm..............2-9 PCMCIA Interface PCA (2686A-4041) ............
  • Page 9 Introduction ....................... 4-3 Configuring the Performance Test Setup ............4-3 Initializing the Performance Test Setup ............4-5 Accuracy Performance Tests ................4-6 Master Alarm Output Tests................4-7 RS-232 Master Alarm Output Test ............4-7 Fluke DAQ Master Alarm Output Test ............ 4-7...
  • Page 10 RS-232 Totalizer Count and Direction Test ..........4-22 RS-232 Totalizer Count and Debounce Test ..........4-23 Fluke DAQ Totalizer Count Test.............. 4-23 Fluke DAQ Totalizer Count and Enable Test........... 4-23 Fluke DAQ Totalizer Count and Direction Test........4-24 Fluke DAQ Totalizer Count and Debounce Test........4-24 Calibration ..................
  • Page 11 Contents (continued) Diagnostic Tool dio..................6-8 Diagnostic Tool rELAy................. 6-9 Diagnostic Tool idS..................6-9 Diagnostic Tool conF..................6-10 Diagnostic Display Test ................6-11 COMM Parameter Reset ................6-11 Using the RS-232 Interface ................6-11 Command Processing..................6-11 Device Configuration ..................6-12 Command Set ....................
  • Page 12 268XA Service Manual...

  • Page 13: List Of Tables

    List of Tables Table Title Page 1-1. 268XA General Specifications ................1-8 1-2. 268X Real-Time Clock and Calendar..............1-9 1-3. Trigger In Specification ..................1-9 1-4. Trigger Out Specification ..................1-9 1-5. Master Alarm Output Specification ............... 1-10 1-6. 2686A - Active Channels and Number of Scans to Card Capacity ....... 1-10 1-7.
  • Page 14 268XA Service Manual 1-37. DIGITAL I/O Specification................... 1-29 1-38. Totalizer Specification ................... 1-30 1-39. DIGITAL I/O Relay Specification................. 1-30 1-40. Models, Options and Accessories ................1-31 2-1. Contoller Connector Description ................2-4 2-2. Backplane Connector Description ................. 2-10 2-3. Range of Buffer Amplifier..................2-19 2-4.

  • Page 15: List Of Figures

    List of Figures Figure Title Page 1-1. 2680A/2685A Device .................... 1-4 1-2. 268XA Chassis ...................... 1-5 2-1. Communication Control System................2-3 2-2. 268XA Main Supply Circuit.................. 2-4 2-3. System Interface Unit .................... 2-6 2-4. FPGA Block Diagram.................... 2-8 2-5. A3 A/D Converter Block Diagram ................ 2-17 2-6.
  • Page 16 268XA Service Manual 8-1. Backplane PCA...................... 8-3 8-2. Controller/System Power PCA ................8-5 8-3. Digital I/O PCA ..................... 8-11 8-4. Backplane Extender PCA ..................8-15 8-5. Extender PCA ......................8-17 8-6. A/D Supply Assembly ................... 8-19 8-7. PCMCIA PCA ....................... 8-21 8-8.
  • Page 17 Introduction ....................... 1-3 Block Diagrams ....................1-5 Specifications ....................1-7 2680A/2686A Combined Specifications............1-7 2680A/2686A General Specifications ............... 1-8 Real-Time Clock and Calendar ................. 1-9 Trigger In Specifications ................... 1-9 Trigger Out Specifications ................1-9 Master Alarm Output Specification..............1-10 Communication I/O ...................
  • Page 18 268XA Service Manual...

  • Page 19: Introduction And Specifications

    Interval timers, alarm conditions, and/or an external signal input can trigger scans. The Fluke DAQ software configures and controls up to 99 268XA devices via an Ethernet connection. The software provides the means to view scan data and log it into files.
  • Page 20 268XA Service Manual alg46f.eps Figure 1-1. 2680A/2686A Device...

  • Page 21: Block Diagrams

    Introduction and Specifications Block Diagrams Block Diagrams A/D Input Card (one of six) Power Isolated Filter Removable 20 Power channel input port with built in Power circuits Switch Matrices temp sensor Daughter (FET or Relay) Card Ctrl Data Data Opto- Microprocessor isolators Ctrl...
  • Page 22 268XA Service Manual Digital I/O Output Card Isolated Digital I/O Removable Power (20) and Connector Totalizer (1) Card Power Daughter Card Ctrl Data Relay Contact Data Microprocessor Opto- (8 pr) and drivers Ctrl isolators Ctrl A/D #1 A/D #2 A/D #3 A/D #4 A/D #5 External Trig in...

  • Page 23: Specifications

    Specifications Specifications are divided into four sections. The first section contains the specifications that apply to both the 2680A and 2686A devices. The second section contains specifications that apply only to the Precision A/D Input (PAI) module. The third section contains specifications that apply only to the Fast A/D Input (FAI) module.

  • Page 24: 2680A/2686A General Specifications

    268XA Service Manual 2680A/2686A General Specifications Table 1-1 provides the general specifications for the 2680A and 2686A devices. Table 1-1. 268XA General Specifications Specification Characteristic Input Channel Capacity Maximum of 120 channels (Precision or Fast Analog Input) per chassis Optional DIO 20 digital input and outputs channels, 8 double pole-single throw relay channels, a totalizer input, and a totalizer enable input.

  • Page 25: Real-Time Clock And Calendar

    Introduction and Specifications Real-Time Clock and Calendar Real-Time Clock and Calendar The next table provides a summary of the battery powered real-time clock and calendar. Table 1-2. 268X Real-Time Clock and Calendar Specification Characteristic Accuracy 1 minute per month for 0 C to 50 C range Battery Life >5 unpowered device years for 20 C to 28 C (68 F to 82.4 F).

  • Page 26: Master Alarm Output Specification

    268XA Service Manual Master Alarm Output Specification The following specifications cover the Master Alarm output. The Master Alarm output is located on the rear panel connector, terminals Master Alarm, and Signal GND. Table 1-5. Master Alarm Output Specification Specification Characteristic Output Voltage - TTL Logical Zero 0.8 V maximum for an Iout of -1.0 mA (1 LSTTL load)

  • Page 27: Precision Analog Input (Pai) A/D Specifications

    Introduction and Specifications Precision Analog Input (PAI) A/D Specifications Precision Analog Input (PAI) A/D Specifications This section includes specifications specific to the PAI A/D instrument by measurement function. Specifications PAI A/D DC Voltage Measurement The following tables provide PAI A/D specifications for the dc voltage measurement function.
  • Page 28 268XA Service Manual Table 1-8. PAI A/D DC Voltage Range and Resolution Specifications Resolution Range Slow Fast 90 mV 0.3 V 300 mV 10 V 30 V 30 V 100 V 300 V 150/300 V 1 mV 3 mV Note 300 V range applies to channels 1 and 11 only. Table 1-9.

  • Page 29: Pai A/D Ac Voltage Measurement Specifications

    Introduction and Specifications Precision Analog Input (PAI) A/D Specifications PAI A/D AC Voltage Measurement Specifications The following tables provide PAI A/D specifications for the ac voltage measurement function. Table 1-10. PAI A/D AC Voltage General Specifications Specification Characteristic Input Impedance in parallel with 100 pF Maximum Crest Factor 3.0 Maximum...
  • Page 30 268XA Service Manual Table 1-12. PAI A/D AC Voltage Accuracy Specifications 1 Year Accuracy + (%input + V) [1] Range Frequency 18 C to 28 C -10 C to 60 C Slow Fast Slow Fast 300 mV 20 to 50 Hz 3%+.25 mV 6%+.5 mV 3.5%+.25 mV...

  • Page 31: Pai A/D 4-Wire Resistance Measurement Specifications

    Introduction and Specifications Precision Analog Input (PAI) A/D Specifications PAI A/D 4-Wire Resistance Measurement Specifications The following tables provide PAI A/D specifications for the 4-wire resistance measurement function. The 4-wire measurements use 2 input channels a decade apart, e.g., channels 4 and 14. Table 1-13.

  • Page 32: Pai A/D 2-Wire Resistance Measurement Specifications

    268XA Service Manual PAI A/D 2-Wire Resistance Measurement Specifications The PAI A/D specifications for the two-wire resistance measurement function is based on the four-wire resistance measurement specification (above) except you add a nominal 5 maximum) positive offset. This value varies for each channel and with temperature (nominal +1%/ºC).

  • Page 33: Pai A/D Thermocouple Per Its-1990 Measurement Specifications

    Introduction and Specifications Precision Analog Input (PAI) A/D Specifications PAI A/D Thermocouple per ITS-1990 Measurement Specifications The following tables provide PAI A/D specifications for the thermocouple measurement function per ITS-1990. Table 1-18. PAI A/D Thermocouple General Specifications Specification Characteristic Input Impedance 100 M minimum in parallel with 300 pF Open Thermocouple Detect...
  • Page 34 268XA Service Manual Table 1-19. PAI A/D Thermocouple Specifications Accuracy + C Thermocouple Resolution 18 C to 28 C -10 C to 60 C ITS90 90 Day 1 Year 1 Year Type Temperature C Slow Slow Fast Slow Fast 600 to 900 1.20 1.40 3.10...
  • Page 35 Introduction and Specifications Precision Analog Input (PAI) A/D Specifications Table 1-19. PAI A/D Thermocouple Specifications (cont.) Accuracy + C Thermocouple Resolution 18 C to 28 C -10 C to 60 C ITS90 90 Day 1 Year 1 Year Type Temperature C Slow Slow Fast...

  • Page 36: Pai A/D Frequency Measurement Specifications

    268XA Service Manual PAI A/D Frequency Measurement Specifications The following tables provide PAI A/D specifications for the frequency measurement function. Table 1-20. PAI A/D Frequency Accuracy Specifications Frequency Measurement Accuracy, 1 Year, -10 C to 60 C Range Resolution Accuracy + (% input + Hz) Slow Fast Slow...

  • Page 37: Fast Analog Input (Fai) A/D Specifications

    Introduction and Specifications Fast Analog Input (FAI) A/D Specifications Fast Analog Input (FAI) A/D Specifications This section includes specifications specific to the FAI A/D instrument by measurement function. FAI A/D DC Voltage Measurement Specifications The following tables provide FAI A/D specifications for the dc voltage measurement function.

  • Page 38: Fai A/D Ac Voltage Measurement Specifications

    268XA Service Manual Table 1-24. FAI A/D DC Voltage Accuracy Specifications Accuracy, 3 + (% input + V) 18 C to 28 C -10 C to 60 C Range 90 Day 1 Year 1 Year Slow Fast Slow Fast Slow Fast 90 mV .01%+20 V...
  • Page 39 Introduction and Specifications Fast Analog Input (FAI) A/D Specifications Table 1-26. FAI A/D AC Voltage Range and Resolution Specifications Resolution Range Minimum Input for Rate Accuracy Slow Fast Full Scale +30,000 +3,000 300 mV 10 V 100 V 20 mV 100 V 1 mV 200 mV...

  • Page 40: Fai A/D 4-Wire Resistance Measurement Specifications

    268XA Service Manual FAI A/D 4-Wire Resistance Measurement Specifications The following tables provide FAI A/D specifications for the 4-wire resistance measurement function. The 4-wire measurements use 2 input channels a decade apart, e.g., channels 4 and 14. Table 1-28. FAI A/D 4-Wire Resistance Temperature Coefficient Specification Characteristic Temperature...

  • Page 41: Fai A/D 2-Wire Resistance Measurement Specifications

    Introduction and Specifications Fast Analog Input (FAI) A/D Specifications FAI A/D 2-Wire Resistance Measurement Specifications The FAI A/D specifications for the two-wire resistance measurement function is based on the four-wire resistance measurement specification (above) except you add a 700 to 1000 positive offset.

  • Page 42: Fai A/D Thermocouple Per Its-1990 Measurement Specifications

    268XA Service Manual FAI A/D Thermocouple per ITS-1990 Measurement Specifications The following tables provide FAI A/D specifications for the thermocouple measurement function per ITS-1990. Table 1-33. FAI A/D Thermocouple General Specifications Specification Characteristic Input Impedance 100 M minimum in parallel with 300 pF Open Thermocouple Detect Operates by injecting a small ac signal into the input after each measurement.
  • Page 43 Introduction and Specifications Fast Analog Input (FAI) A/D Specifications Table 1-34. FAI A/D Thermocouple Specifications (cont.) Accuracy + C Thermocouple Resolution 18 C to 28 C -10 C to 60 C ITS90 90 Day 1 Year 1 Year Type Temperature C Slow Slow Fast...

  • Page 44: Fai A/D Frequency Measurement Specifications

    268XA Service Manual Table 1-34. FAI A/D Thermocouple Specifications (cont.) Thermistor Accuracy + C 90 Day 1 Year Temp C Range* Slow Slow -40 to 150 100 to 100 m 0.51 18 to 23 C Steinhart – Hart Equation: 1/(T Kelvin) = A + B*(ln ) + C*(ln Default constants are supplied only for a YSI (type 004) 2,252...

  • Page 45: Digital Input/Output Module

    Introduction and Specifications Digital Input/Output Module Digital Input/Output Module The following specifications apply to the DIO Module. The module contains digital open collector outputs, relay contacts, digital inputs, and totalizer. XWWarning The DIO module is rated as a CAT I device. Digital Input/Output Specifications Table specifications provides a summary of the Digital I/O specifications for the 10 Digital I/O lines (0 to 19).

  • Page 46: Totalizer Input Specifications

    268XA Service Manual Totalizer Input Specifications The following table provides a summary of the Totalizer Input specifications. The Totalizer Input is located on the Output Module connector, terminals TOI and GND. The totalizer will be able to increment or decrement depending on the input on a separate digital input channel.

  • Page 47: Options And Accessories

    Fluke Development Software from InduSoft 2680A-DLL Fluke DLL Library routines for the development of device drivers 2680A-OPC Fluke OPC Software. Used to configure a PC to act as an OPC server and provide virtual contact with a 268XA device. 1-31...
  • Page 48 268XA Service Manual 1-32...

  • Page 49: Theory Of Operation

    Chapter 2 Theory of Operation Title Page Introduction ....................... 2-3 Main Power Supply..................2-5 Secondary Supplies ..................2-5 Out-Guard Overview..................2-5 Microprocessor ..................2-6 FPGA ......................2-7 Other Bus Devices ..................2-8 Serial Devices ................... 2-9 Trigger In/Out, Master Alarm..............2-9 PCMCIA Interface PCA (2686A-4041) ............
  • Page 50 268XA Service Manual Input Protection..................2-18 Input Signal Conditioning................. 2-18 Function Relays ..................2-18 Channel Selection Circuitry..............2-19 DC Volts and Thermocouples Measurement Circuitry......2-19 Ohms and RTD Measurement Circuitry ........... 2-20 AC Volts Measurement Circuitry............. 2-22 Frequency Measurements ................. 2-23 Active Filter (ACV Filter) ................

  • Page 51: Introduction

    Theory of Operation Introduction Introduction This chapter is intended to provide a detailed description and analysis, where appropriate, of the printed circuit board assemblies (PCAs) used in the 268XA. Figure 2-1 below is an overall block diagram of the communication control system. Note that the blocks labeled "Module #n"...

  • Page 52: 268Xa Main Supply Circuit

    10/100 Base T Ethernet and RS-232. Refer to Chapter 8 for a schematic of the 2680A-4004 board. Table 2-1 provides a summary of all the connectors on the 4004 PCA.

  • Page 53: Main Power Supply

    Theory of Operation Introduction Main Power Supply The power supply circuitry is contained on page 6 of the 2680-1004 schematic. The main supply consists of 2 switching regulators, U301 and U303. U301 takes either a 9 V to 42 V dc source from P6 pins 1 and 2 or a 10:1 stepped down 50/60 Hz 95 V to 265 V ac line voltage from P9 pins 3 and 4 as an input.

  • Page 54: Microprocessor

    268XA Service Manual Microprocessor The processor used in the 268XA (U6) is a Motorola MPC855T, see page 2 of the 1004 schematic. Its architecture is very similar to the 683xx series of embedded communications controllers that have been used on many product lines, including NetDAQ and 55xx series calibrators, except that instead of a 16 bit 68000 processor core with no instruction or data cache, the MPC855T has a 32 bit power PC core with 4 Kbytes of both L1 instruction and data cache.

  • Page 55: Fpga

    Theory of Operation Introduction FPGA The gate array (U25) in the 268XA is an Altera ACEX series EP1K100QC208-1. It is on page 5 of the 1004 schematic. It has 48Kbits of embedded dual port RAM configurable in 12 blocks of various width/depth combinations, as well as approximately 100K gates. This design uses about 55 % of the logic cells, and about 25 % of the memory bits, spread out over all 12 blocks, and has a maximum clock frequency of 57.4 MHz.

  • Page 56: Other Bus Devices

    268XA Service Manual URT URT URT URT URT URT Clock Keypad Generator key_ck Guard xing Address Decode Trigger In/Out Data Mux Entity alg109f.eps Figure 2-4. FPGA Block Diagram Other Bus Devices The microprocessor’s external bus controller, in addition to the fpga, communicates with onboard SDRAM, onboard flash ROM and PCMCIA flash memory cards.

  • Page 57: Serial Devices

    Theory of Operation Introduction This particular series of devices is presently available in 2 other sizes, 8 MB and 16 MB, provisions have been made in this design for using those devices if necessary, with minimal required rework. U20 is programmed and powered from Vcc, there is no additional 12 V programming voltage required for Strataflash devices.

  • Page 58: Pcmcia Interface Pca (2686A-4041)

    PCMCIA card, no other devices should be powered from this supply. This board plugs into P4 on the 2680A-4004 PCA. It is a daughter card that is only installed if the instrument is a 2686 chassis, as opposed to a 2680 chassis which has no PCMCIA option.

  • Page 59: Display Interface

    Theory of Operation Module Power Supply PCA (268XA-4031) Display Interface The display controller interface on the backplane consists of a tri-stateable levelshifter/buffer, some decoupling capacitors, and the display ribbon cable connector (P8). The levelshifters (U1, 2, 3) need to be tri-stateable because, when the microprocessor is talking to the calibration EEPROMs, the display should not receive those transmissions.

  • Page 60: Microcontroller

    268XA Service Manual Microcontroller A Texas Instrument MSP430P337A mixed signal microcontroller is the heart of the DIO PCA. The microcontroller, U4, features bi-directional digital ports, a built in UART and internal timers for controlling operation. A quartz crystal operating at 32.8 kHz provides the main clock signal for the microcontroller.

  • Page 61: Digital Input Buffers

    Theory of Operation Digital Input/Output PCA Digital Input Buffers Since the 20 Digital Input Buffers are identical in design, only components used for Digital Input 0 are referenced in this description. If the Digital Output Driver (U13 Pin 13) is “off”, the input to the Digital Input Buffer is determined by the voltage level at P6 Pin A1.

  • Page 62: Totalizer Input

    268XA Service Manual Totalizer Input The Totalizer Input circuit consists of Input Protection, a Digital Input Buffer circuit, and a Totalizer Debouncing circuit. The Digital Input Buffer for the Totalizer is protected from electrostatic discharge (ESD) damage by R31 and C48. Refer to the detailed description of the Digital Input Buffer circuit for more information.

  • Page 63: Analog Measurement Processor

    Theory of Operation A/D Theory of Operations Analog Measurement Processor The Analog Measurement Processor (A3U30) provides input signal conditioning, ranging, and frequency measurement. This custom integrated circuit is controlled by the inguard A/D Microprocessor (A3U5). The A/D Microprocessor communicates with the main Controller/System Power PCA over a serial interface.

  • Page 64: Open Thermocouple Check

    Motorola 68302 microprocessor. Flash ROM Serial Interface to the Main Board. A Fluke manufactured Stallion IC (U30) for range selection and frequency measurements. Multi-Slope A/D converter comprised of discrete components and an FPGA (Field Programmable Gate Array) (U18).

  • Page 65: A3 A/D Converter Block Diagram

    Theory of Operation A/D Theory of Operations A4 Analog Input EMI Filters Ch11 to 20 Ch1 to 10 Scanner Relays Scanner Relays Relay Drivers Treeing Relays Ohms Current Source Voltage Input Input Protection Signal Conditioning Selectable Gains DC Buffer Amplifier x4.021 x32.168 +3.45V dc...

  • Page 66: Stallion Chip

    268XA Service Manual Stallion Chip The Stallion IC (A3U30) is a Fluke-designed 100-pin CMOS device that performs the following functions under control of the A/D microprocessor (A3U5): Input signal routing Input signal conditioning A/D buffer amplifier range switching Frequency measurements...

  • Page 67: Channel Selection Circuitry

    Theory of Operation A/D Theory of Operations Channel Selection Circuitry Channel selection is done using reed relays on the PAI and by optically coupled solid-state relay on the FAI. Channel selection is done by a set of 24 relays organized in a tree structure.

  • Page 68: Ohms And Rtd Measurement Circuitry

    268XA Service Manual Table 2-4. Measurement Matrix for DC Volts Full-Scale DC Full-Scale Gain of DC Volts Input to Buffer Range DC Volt Output of Buffer Multislope Control Range Input to Stallion Stallion Amplifier Signal 90 mV Direct 90 mV 32.168 300 mV Direct...

  • Page 69: Rtd Measurement Simplified Schematic

    Theory of Operation A/D Theory of Operations Table 2-5. Measurement Matrix for Ohms Full-Scale Full-Scale Full-Scale DC Volts Buffer Input to Output of Gain of DC input to Range Ohms Current Stallion Stallion Buffer Multislope Control Range Used (dc volts) (dc volts) Amplifier Signal...

  • Page 70: Ac Volts Measurement Circuitry

    268XA Service Manual AC Volts Measurement Circuitry. AC-coupled voltage inputs are scaled by an ac buffer (A3U29), converted to dc by a true RMS ac-to-dc converter (A3U26), filtered by an active ac volt filter, then sent to the Stallion IC, the Buffer Amplifier, and the A/D Conversion Circuitry (see Table 2-6). The HI input is switched to the ac buffer through dc blocking capacitor A3C80.

  • Page 71: Frequency Measurements

    Theory of Operation A/D Theory of Operations A3K25 A3Q15 A3Q12 A3U29 A3K25 HI SENSE A3Z6 A3R11 A3C80 1.111M A3C72 2W FUS A3R127 A3Z6 A3Z6 A3CR2 12.25K 111.1K A3C71 A3L52 A3K27 A3Z6 2.776K A3R146 A3R119 A3Z6 115.7 AD LOW RMSOUT To Pin 31 of A3U30 A3U26 A3Z2 4.95K...

  • Page 72: Active Filter (Acv Filter)

    268XA Service Manual Active Filter (ACV Filter) The active filter is used only for V ac measurements to filter out the ac ripple and noise present on the output of the RMS converter. The filter uses an op-amp internal to the Stallion Chip, resistors A3R102, A3R103, and A3R104, capacitors A3C57, A3C58, and A3C59.

  • Page 73: Integrate

    Theory of Operation A/D Theory of Operations Table 2-7. Analog/Digital Converter Measurement Cycle State Counts Time Autozero 200.0 s Integrate 491.4 s Deintegrate1 102.4 s Deintegrate2 38.4 s Overhead 1.333 s Total 833.533 s Integrate The integrate state is when the input voltage is actually connected to the integrator. PREF and NREF are each switched off and on 10 to 20 times during this state and DREF is still off, INT is on, AZ is off, and the CMP signal is switching off and on.

  • Page 74: Integrator Output Wavefrom For Input Near + Full Scale

    268XA Service Manual This can also be anywhere from 1 to 60 counts, but at this point, the output should be within 1 count of reaching zero volts. Next, another hold state is entered into for 1 count, followed by PREF until CMP goes high. This sets up the final DREF to always approach zero from the same direction.

  • Page 75: Deintegrate2

    Theory of Operation A/D Theory of Operations 0v dc f2-13.eps Figure 2-11. Integrator Output Waveform for Input Near - Full Scale Deintegrate2 Deintegrate begins with the turning on of DREF. This reference applies 1/16th of the current of NREF so the approach to zero is slower and more accurate. Correspondingly, the internal FPGA counter counts this time at 1/16th the value of NREF time.

  • Page 76: Open Thermocouple Detect Circuitry

    268XA Service Manual Communication with the Controller/System Power PCA is done using the CordxRx line to receive and the CordxTx line to send serial data. On the A/D side, these signals are called RECV DATA and XMIT DATA (pins A3U5-53 and A3U5-54 respectively). The RESET* signal is asserted on power-up for reset and during operation when a break signal is received from A1U4.

  • Page 77: A31 A/D Power Supply Circuit Description

    Theory of Operation A/D Theory of Operations Temperature sensor transistor A4Q1 outputs a voltage inversely proportional to the temperature of the input channel terminals. This voltage is 0.6 V dc at 25 C, increasing 2 mV with each degree decrease in temperature, or decreasing 2 mV with each degree increase in temperature.

  • Page 78: Commands

    268XA Service Manual Commands A command consists of a six-byte packet sent from the outguard to the inguard. The most-significant four bits of the first bytes define the following command types: Perform Scan. Perform a Self-Test. Return A/D Main Firmware Version. Return A/D Boot Firmware Version.

  • Page 79: Perform Self-Test

    Theory of Operation A/D Theory of Operations Response Packets Returned The inguard returns one response packet for the reference junction reading if any of the measured channels is a thermocouple channel, followed by a response packet for each channel measured, returned in ascending channel order, followed by a response packet for each housekeeping reading specified by the scan command.

  • Page 80: Set Global Configuration

    268XA Service Manual Response Packet Format The response consists of five ASCII characters (plus the checksum byte), in the form Bxxyy, where B indicates boot software, xx are the two digits of the major version number, and yy are the two digits of the minor version number (there is an implicit decimal point between the two).

  • Page 81: Checksums

    Theory of Operation A/D Theory of Operations If the Next bit is 1, the inguard does the next housekeeping reading indicated by its internal schedule. This is the same schedule used for a housekeeping timeout. If the Do2 bit is 1, the inguard does the two reference balance readings. If the PS bit is 1, the inguard presets the function relays for the first defined channel.

  • Page 82: Hardware Elements

    268XA Service Manual The channel scanner relays select the desired channel to be measured and route it to the function relays. The function relays route the signal to the appropriate portion of the Signal Conditioning circuitry, depending on the function being measured (V ac, V dc, ohms, etc.).

  • Page 83: Function Relays

    Theory of Operation A/D Theory of Operations Table 2-9. Channel Bits Channels Enabled 1, 11 2, 12 3, 13 4, 14 5, 15 6, 16 7, 17 8, 18 9, 19 10, 20 The time required for the channel switches to settle is given in Table 2-10. Note that for both the FAI and the PAI, the switches are guaranteed to have a select time that is longer than their deselect time.

  • Page 84: Stallion Chip And Signal Conditioning

    6 ms Stallion Chip and Signal Conditioning The Stallion Chip (A3U30) is a Fluke-custom IC that contains assorted switches, amplifiers, and the frequency counter. The chip contains registers that the A3U5 A/D microprocessor may read and write to configure the chip and obtain frequency readings.
  • Page 85 Theory of Operation A/D Theory of Operations The Stallion switch settings for the various function/range combinations are given in Table 2-13. Table 2-13. Stallion Switch Settings Stallion Settings Function S Switches Other Switches V dc 90 mV 17 23 35 37 39 44 50 64 ACR4 FPWR RPCTL...
  • Page 86 268XA Service Manual Table 2-13. Stallion Switch Settings (cont) Stallion Settings Function S Switches Other Switches Zero BR1 23 35 37 39 44 64 ACR4 ACR5 FPWR RPCTL Zero BR2 23 35 37 39 44 64 ACR4 ACR5 FPWR RPCTL Zero BR3 23 35 37 39 44 64 ACR4...

  • Page 87: A/D

    Theory of Operation A/D Theory of Operations The multi-slope A/D converter in the instrument uses a hardware state machine (A3U18) to control the switching of the voltage references during the A/D conversion. This state machine also contains the counters that measure how long each reference is switched in, and provides the A3U5 A/D microprocessor with its interface to the A/D.
  • Page 88 268XA Service Manual Control Signals Several signals are used by the A3U5 A/D microprocessor to control and receive state information from the A/D state machine (A3U18). The Trigger line, used to indicate to the A/D when to begin a reading, was discussed previously. The A/D state machine has several modes of operation: perform conversion (measure input);...
  • Page 89 Theory of Operation A/D Theory of Operations Counters The counters in the A/D state machine (A3U18) are accessed through a synchronous serial interface. This interface is connected to the SCP port of the A3U5 A/D microprocessor, which is also connected to the Stallion chip. Chip-select lines are used to indicate the device the A3U5 A/D microprocessor is communicating.

  • Page 90: Discharge Signal

    268XA Service Manual Z = zero offset. Zero offsets are also covered in “Zero Offset Readings” later in this chapter. DISCHARGE Signal The signal DISCHARGE is driven by the A3U5 A/D microprocessor (pin 59) through one of its parallel port pins and controls the discharge of certain filter capacitors. This line is normally left low.

  • Page 91: Measurement Types

    Theory of Operation A/D Theory of Operations Measurement Types There are several steps that you must perform at the beginning of any channel measurement: Set function relays. See “Function Relays” earlier in this chapter. This is a relatively slow operation and should be done only if the relay positions actually need to change. Set tree and channel switches.
  • Page 92 268XA Service Manual Thermocouple readings also require an isothermal block reference junction reading to be taken. If any thermocouple channels are measured in a scan, a reference junction measurement is taken first, before any channel measurements. Reference Junction The reference junction reading is similar to a V dc reading. However, no channel selection or function relay switching is required;...

  • Page 93: Autoranging

    Theory of Operation A/D Theory of Operations V ac Discharge Mode After a frequency or V ac reading, the hardware is configured to discharge certain signal conditioning capacitors, charged during the measurement. This is done to avoid disturbing the measurement of a subsequent V ac or frequency measurement. The function relays are set to the V ac discharge position, as given in Table 2-11, Function Relays, and the DISCHARGE signal is set high.

  • Page 94: Housekeeping Schedule

    268XA Service Manual Table 2-18. A/D Reading to Average to Obtain a Reference Balance Measurement Instrument Reading Rate Fast Reading Rate Medium Reading Rate Slow 5 (60 Hz) 45 (60 Hz) 6 (50 Hz) 48 (50 Hz) 5 (60 Hz) 6 (50 Hz) There are two reference balance readings: one with both references on, and one with both references off.

  • Page 95: Self-Tests

    Theory of Operation A/D Theory of Operations Self-Tests There are two series of self-tests performed by the inguard: those done automatically at power-up, and those done in response to a self-test command from the outguard. Power-Up Self-Tests On power-up the inguard performs a ROM checksum test and a destructive RAM test. If either of these tests fail, the inguard treats it as a fatal error and enters the boot monitor.
  • Page 96 268XA Service Manual 2-48...

  • Page 97: Maintenance

    Chapter 3 Maintenance Title Page Introduction ....................... 3-3 Self-Test Diagnostics and Error Codes ............. 3-3 Cleaning......................3-6 AC Fuse Replacement ..................3-7 DC Fuse Replacement ..................3-8...
  • Page 98 268XA Service Manual...

  • Page 99: Introduction

    Otherwise, package the device securely (using the original container, if available), and mail it to the nearest Fluke Service Center. Include a description of the problem. Fluke assumes no responsibility for damage in transit.
  • Page 100 268XA Service Manual If the PC card has a configuration in the scan data that is inconsistent with the current module mix, scanning will not begin. When using a PC card, you must either format the PC card or modify the module mix to match the PC card scan configuration before scanning can begin.
  • Page 101 Maintenance Self-Test Diagnostics and Error Codes Table 3-1. Self-Test Codes (cont) Self-Test Code Description Module 3 zero offset measurement unreasonable Module 3 reference balance measurements unreasonable Module 3 overload detection failed Module 3 open thermocouple detection failed Module 4 calibration constants corrupt Module 4 calibration procedures incomplete Module 4 A/D failure Module 4 zero offset measurement unreasonable...

  • Page 102: Cleaning

    268XA Service Manual Table 3-1. Self-Test Codes (cont) Self-Test Code Description PAI expected in slot 3 FAI expected in slot 3 PAI expected in slot 4 FAI expected in slot 4 PAI expected in slot 5 FAI expected in slot 5 PAI expected in slot 6 FAI expected in slot 6 DIO expected in slot 6...

  • Page 103: Ac Fuse Replacement

    Maintenance AC Fuse Replacement AC Fuse Replacement The device uses a 1/2 ampere, 250 V, slow blow line fuse in series with the mains power supply. To replace the fuse, refer to Figure 3-1 and the following procedure: XWWarning To avoid electrical shock, do not operate the device without the cover properly installed.

  • Page 104: Dc Fuse Replacement

    Service Manual DC Fuse Replacement The 2680A/2686A devices use a 4 ampere, 250 V, slow blow fuse in series with the dc supply “+” input. This fuse is mounted on the main controller board inside the chassis. See Figure 3-2 for an illustration of the dc fuse location.

  • Page 105: Dc Fuse Location

    Maintenance DC Fuse Replacement Fuse, 4A, 250V, Slow, 5MM X 20MM, Bulk alg111f.eps Figure 3-2. DC Fuse Location...
  • Page 106 268XA Service Manual 3-10...

  • Page 107: Performance Verification

    Accuracy Performance Tests ................4-6 Master Alarm Output Tests................4-7 RS-232 Master Alarm Output Test ............4-7 Fluke DAQ Master Alarm Output Test ............ 4-7 Trigger Input Tests..................4-7 RS-232 Trigger Input Test ................ 4-7 Fluke DAQ Trigger Input Test ..............4-8 Trigger Output Tests ..................
  • Page 108 268XA Service Manual Fluke DAQ Totalizer Count and Enable Test........... 4-23 Fluke DAQ Totalizer Count and Direction Test........4-24 Fluke DAQ Totalizer Count and Debounce Test........4-24...

  • Page 109: Introduction

    18 to 28 °C, and a relative humidity of less than 70%. The digital tests can be run either through the RS-232 port or by using Fluke DAQ software. With most procedures, you can use either method to verify functionality. For the RS-232 tests, you will also need to use a program such as HyperTerminal to perform the test.
  • Page 110 Oscilloscope Alternative Equipment List Device Type Recommended Model Multiproduct Calibrator Fluke 5520 (Do not use for FAI ohms calibration below 1.9 k ) Function/Signal Generator Philips PM5139 or HP33120A or equivalent Decade Resistance Source General Resistance RDS 66A or equivalent...

  • Page 111: Initializing The Performance Test Setup

    3. Apply Host Computer Power Apply power to the host computer. 4. Open Fluke DAQ Software You can use Start | Programs, double-click on a setup file shortcut on the Windows desktop, or double-click on a setup file name in the Windows Explorer or File Manager.

  • Page 112: Accuracy Performance Tests

    The tests for the Master Alarm output, Trigger Output, Trigger Input, and DIO signal lines can either be tested using Fluke DAQ software or using commands through the RS-232 port. For the RS-232 tests, you will also need to use a program such as HyperTerminal to perform the test.

  • Page 113: Master Alarm Output Tests

    GND test lead, to check if the voltage is greater than +3.8 V dc. 3. Verify Configuration Channel 1 for V dc In Fluke DAQ, verify channel 1 is configured for V dc, 3 V range.

  • Page 114: Fluke Daq Trigger Input Test

    External Trigger with an Interval 2 of 1 second. Be sure Interval Trigger and Alarm Trigger are not enabled. 2. Verify Configuration Channel 1 for V dc In Fluke DAQ, verify channel 1 is configured for V dc, 3 V range.

  • Page 115: Volts Dc Accuracy Test (Pai Module)

    Measurement accuracy applies to all channels, not just the channel used for the test. 1. Configure Channel 1 for V dc Using the Fluke DAQ software, configure the PAI channel 1 for V dc, 90 mV range.

  • Page 116: Volts Dc Accuracy Test (Fai Module)

    The following procedure tests the accuracy of the volts dc function for the 268XA. Measurement accuracy applies to all channels, not just the channel used for the test. 1. Configure Channel 1 for V dc Using the Fluke DAQ software, configure channel 1 for V dc, 90 mV range.

  • Page 117: Volts Ac Accuracy Test

    FAI modules. Measurement accuracy applies to all channels, not just the channel used for the test. 1. Configure Channel 1 for V ac Using the Fluke DAQ software, configure channel 1 for V ac, 300 mV range. 2. Open Spy Open the Spy window under the Configuration dialog.

  • Page 118: Analog Channel Integrity Test

    1 terminals. Reinstall the Universal Input module. 2. Configure Channel 1 for Thermocouples In Fluke DAQ, configure channel 1 for Thermocouples with Range (thermocouple type) K. 3. Open Spy Open the Spy window under the Configuration dialog.

  • Page 119: 2-Wire Resistance Accuracy Test (Pai) - Optional

    You may also use the 5700A resistance calibration output instead of the Decade Resistance Source. Tables are provided for both connections. 2. Configure Channel 1 for Ohms In Fluke DAQ, configure channel 1 for Ohms-2W, 300 range. 3. Open Spy Open the Spy window under the Configuration dialog.

  • Page 120: 2-Wire Resistance Accuracy Test (Fai Module) - Optional

    You may also use the 5700A resistance calibration output instead of the Decade Resistance Source. Tables are provided for both connections. 2. Configure Channel 1 for Ohms In Fluke DAQ, configure channel 1 for Ohms 2W, 30 k range.
  • Page 121 Performance Verification Accuracy Performance Tests Resistance Range* Decade Resistor Minimum Reading Maximum Reading Short Circuit (Zero) 30 k 30 k 29 k 29.681 k 30.019 k 300 k 290 k 289.07 k 292.63 k 2.9 M 2.8607 M 2.9410 M *The resistance accuracy in this table makes allowance for up to 0.1 Ohm of lead wire resistance plus 0.01% decade resistance tolerance.

  • Page 122: 4-Wire Resistance Accuracy Test (Pai Module)

    Refer to Figure 4-4 for the 5700A 4-wire connections. 2. Configure Channel 1 for Resistance In Fluke DAQ, configure channel 1 for Ohms 4W, 300 range. 3. Open Spy Open the Spy window under the Configuration dialog.
  • Page 123 Performance Verification Accuracy Performance Tests 13 14 15 16 17 18 19 20 SOURCE H L H L H L H L H L H L H L H L H L (4-WIRE) INPUT MODULE SENSE H L H L H L H L H L H L H L H L H L (4-WIRE) 5700A OUTPUT...
  • Page 124 268XA Service Manual 4. Verify Accuracy Configure the Decade Resistance Source for the output values below and verify the Spy window measurement is between the minimum and maximum values. Change the channel 1 range as required (see Step 2). Resistance Range Decade Resistor Minimum Reading Maximum Reading...

  • Page 125: 4-Wire Resistance Accuracy Test (Fai Module)

    Refer to Figure 4-4 for the 5700A 4-wire connections. 2. Configure Channel 1 for Resistance In Fluke DAQ, configure channel 1 for Ohms 4W, 300 range. 3. Open Spy Open the Spy window under the Configuration dialog.

  • Page 126: Digital Input/Output Tests

    268XA Service Manual Resistance Range 5700A Minimum Reading Maximum Reading Short Circuit (Zero) 189.86 190.14 Short Circuit (Zero) 1.9 k 1.8986 k 1.9014 k 30 k 19 k 18.986 k 19.014 k 300 k 190 k 188.90 k 191.10 k 1.9 M 1.8733 M 1.9267 M...

  • Page 127: Fluke Daq Digital Input/Output Test

    Fluke DAQ Digital Input/Output Test 1. Open Communication Dialog Use the Communication dialog in Fluke DAQ for this test. Click on the DIO module icon in the TreeView display to see the DIO settings. The DIO dialog will only work if the DIO module is installed in the device and has been inserted using the Configuration dialog.

  • Page 128: Totalizer Tests

    DIO channel 0 signal line to the totalizer enable line en) in the connector module. If you are using Fluke DAQ to perform the totalizer tests, select the DIO from TreeView in the Configuration dialog. In the DIO Configuration dialog, Set the start count in the DIO Configuration dialog to 0, deselect debounce (if selected), and select direction as up.

  • Page 129: Rs-232 Totalizer Count And Debounce Test

    7. Disconnect Signal Generator Disconnect the signal generator. Testing of the Digital Input/Output signal lines can be done through the RS-232 port (using HyperTerminal or other communication program) or through the Fluke DAQ software. Either method can be used. The Digital Input/Output Test checks the 20 Digital I/O lines through the Digital I/O connector module for correct operation.

  • Page 130: Fluke Daq Totalizer Count And Direction Test

    9. Select DIO Click on the Communication icon and select the DIO from TreeView. 10. Enable Totalizer Deselect the DIO channel 0 to enable the totalizer. Fluke DAQ Totalizer Count and Direction Test 1. Configure DIO In the Configuration dialog, select the DIO from TreeView. In the DIO Configuration dialog, set the start count to 0, deselect debounce (if selected), and select direction as down.

  • Page 131: Calibration

    Chapter 5 Calibration Title Page Introduction ....................... 5-3 Calibration ......................5-3 Methods of Calibration..................5-3 Preparing for Calibration................... 5-3 Ending Calibration..................... 5-6 RS-232 Device Configuration Parameters ............5-6 Manual Calibration Procedure................5-7 Manual Calibration Commands................. 5-9 V DC Calibration Procedure ................. 5-10 V AC Calibration Procedure .................
  • Page 132 268XA Service Manual...

  • Page 133: Introduction

    There are no calibration procedures for the 2680A/2686A chassis nor for the DIO module. Only verification tests are run on those items. The calibration is only performed on the analog A/D modules such as the precision A/D input module (PAI) and the fast A/D input module (FAI).
  • Page 134 268XA Service Manual 2. Wire the Universal Input Module so the high and low inputs to channels 1 and 11 are externally available. In addition, a four-wire short must be applied to channels 2 and 12. (See Figure 5-2.) Plug the module into the device. 3.

  • Page 135: Device And Host Computer Calibration Setup

    Calibration Preparing for Calibration RS43 Null Modem Cable (DB-9 Female to DB-9 Female) RS-232 Port COM1 (DB-9) 268XA Host Computer f4-05.eps Figure 5-1. Device and Host Computer Calibration Setup H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L H L CH11...

  • Page 136: Ending Calibration

    OFF to clear CAL from the primary display. RS-232 Device Configuration Parameters When CAL is shown in the 2680A/2686A display, it indicates that you are in the calibration mode. The device configuration parameters are set as listed in Table 5-1.

  • Page 137: Manual Calibration Procedure

    Calibration Manual Calibration Procedure Universal 13 14 15 16 17 18 19 20 Input SOURCE H L H L H L H L H L H L H L H L Module Channel 11 (4-WIRE) Wires SENSE H L H L H L H L H L H L H L H L 2-WIRE (4-WIRE) COMP...
  • Page 138 268XA Service Manual f4-06bmp.bmp 5. Select the Terminal Preferences command from the Settings menu. Check the boxes Local Echo and Outbound (see below). Click OK. f4-08bmp.bmp...

  • Page 139: Manual Calibration Commands

    Calibration Manual Calibration Commands 6. Press the <Enter> key a few times and notice the => returns, indicating a successful connection (see below). If you do not receive these returns, the RS-232 link is not operating. Check the communication parameter settings and cabling. f4-07bmp.bmp Manual Calibration Commands The calibration procedures are performed in the terminal mode using the commands...

  • Page 140: Dc Calibration Procedure

    268XA Service Manual Table 5-3. Manual Calibration Command Responses Response Description => indicates the command was executed correctly. !> indicates that a device-dependent error was generated and the calibration step could not be executed. Verify that the input to channel 1 is the correct value and polarity, is connected correctly, and the 5700A is in the Operate mode.
  • Page 141 Calibration Manual Calibration Commands Table 5-4. Manual V DC Calibration Command Response Action CAL 1 => Puts 268XA in V dc calibration. CAL_REF? +90.0000E-3 Use the 5700A to source 90 mV dc. CAL_STEP? +90.0000E-3 268XA computes the calibration constant and returns the calibrated reading.

  • Page 142: Ac Calibration Procedure

    268XA Service Manual V AC Calibration Procedure The V ac calibration procedure calculates gain and offset calibration constants for all of the V ac ranges. Complete the following procedure to manually calibrate the V ac function. 1. If you have not already done so, complete the procedure “Preparing for Calibration” earlier in this chapter.

  • Page 143: Resistance Calibration Procedure

    3. Complete the sequence of manual steps shown in Table 5-6. The default values were chosen assuming that a Fluke 5700A will be used to supply the reference resistors. For each range, channels 1 and 2 are configured to four-wire ohms and a measurement is made for each channel.
  • Page 144 268XA Service Manual channel 1 provides the full scale reading and measuring the four-wire short on channels 2 and 12 determines the zero offset error. The four-wire ohms gain and offset calibration constants are determined from these two measurements. The 5700A provides a limited set of reference resistors where the best resistor for each range is at 63.3% of full scale.

  • Page 145: Frequency Calibration Procedure

    Calibration Manual Calibration Commands Table 5-6. Manual Resistance Calibration Command Response Action CAL 3 => Puts 268XA in resistance calibration. CAL_REF? +190.000E+0 Use the 5700A to source 190 CAL_STEP? +190.000E+0 268XA computes the calibration constant and returns the calibrated reading. Allow several seconds. CAL_REF? +1.90000E+3 Use the 5700A to source 1.9 k .
  • Page 146 268XA Service Manual An execution error !> is returned by the CAL_STEP? command if the frequency measurement is off by more than 5% from the target. When an error is detected, the cal constant is not updated, and the procedure remains at the same step. When CAL_STEP? reports an execution error !>...

  • Page 147: Diagnostic Testing And Troubleshooting

    Chapter 6 Diagnostic Testing and Troubleshooting Title Page Introduction ....................... 6-3 Servicing Surface-Mount Assemblies ............... 6-3 Error Detection ....................6-4 FLASH ROM Parameter Defaults ..............6-7 Background Testing ..................6-7 Retrieving Error Codes using RS-232............6-8 Selecting the Diagnostic Tools ................6-8 Diagnostic Tool dio..................
  • Page 148 268XA Service Manual Totalizer Enable..................6-42 Digital Output PCA Troubleshooting ............6-42 A3 A/D Converter Module Troubleshooting ..........6-42 A3 Kernel....................6-42 Break/Reset Circuit................... 6-43 Out of Tolerance Readings ............... 6-43 Troubleshooting Relay Problems.............. 6-44 A4 Analog Input PCA Troubleshooting............6-44 Troubleshooting Calibration Failures..............

  • Page 149: Introduction

    Diagnostic Testing and Troubleshooting Introduction Introduction The 268XA device provides error code information and semi-modular design to aid in troubleshooting. This section explains the error codes and describes procedures needed to isolate a problem to a specific functional area. Finally, troubleshooting hints for each functional area are presented.

  • Page 150: Error Detection

    268XA Service Manual especially clean to ensure a strong connection. An oxidized PCA pad causes the solder to wick up the component lead, leaving little solder on the pad itself. Error Detection At power-up, the device software performs self-tests. If any errors in device operation are detected, they are reported on the device front panel with Error in the primary display and a decimal error code number in the secondary display.
  • Page 151 Diagnostic Testing and Troubleshooting Error Detection Table 6-1. Self-Test Error Codes Self-test Front Panel Err Code Description 0x00000000 No self-test errors 0x00000001 Boot block ROM checksum failed 0x00000002 Bad outguard main image in ROM 0x00000004 Boot block RAM failed 0x00000008 Display test failure 0x00000010 Display not responding...
  • Page 152 268XA Service Manual Table 6-1. Self-Test Error Codes (cont) Self-test Front Panel Err Code Description Second 32-bit self-test code 0x00000000 No self-test error. 0x00000001 Module 3 Calibration constants corrupt 0x00000002 Module 3 Calibration Procedures Incomplete 0x00000004 Module 3 A/D failure 0x00000008 Module 3 Zero offset measurements unreasonable 0x00000010...

  • Page 153: Flash Rom Parameter Defaults

    Error Detection FLASH ROM Parameter Defaults The FLASH ROM (System Power/Controller Board 2680A-4004) parameters are reset to defaults following the first power-on and following power-cycles after any FLASH ROM parameters are discovered to be corrupt. These defaults are listed in Table 6-2.

  • Page 154: Retrieving Error Codes Using Rs-232

    268XA Service Manual Retrieving Error Codes using RS-232 You can retrieve error codes from the device using the device rear-panel RS-232 port and an ASCII terminal, or PC running ASCII terminal emulation. Complete the following procedure to retrieve error codes from the device using an RS- 232 connection.

  • Page 155: Diagnostic Tool Relay

    Diagnostic Testing and Troubleshooting Selecting the Diagnostic Tools 1. Select the dio diagnostic tool using the procedure “Selecting the Diagnostic Tool Menu.” 2. Use the left/right arrows to select the desired dio line dio19 to dio0. The format is nnnn-nnnn-nnnn-nnnn-nnnn, representing dio lines dio19 to dio0, respectively. The secondary display shows the selected line, for example, dio:19.

  • Page 156: Diagnostic Tool Conf

    268XA Service Manual Table 6-4. Device Firmware Descriptions Primary Display* Secondary Display 2680A -or- 2686A inStr (Device Model Number) 01.00 Lc (logger GUI compatibility e.g.. embedded is compatible with GUI version 1 or higher) 02.00 diSP (Display CPU Version) 1.2-1 boot (Main Boot Version) 01.00...

  • Page 157: Diagnostic Display Test

    Diagnostic Testing and Troubleshooting Using the RS-232 Interface Diagnostic Display Test For a constant front panel display with all segments lit, turn off the device, then turn the power on again while holding down the front panel  key. After the device beeps, release the key.

  • Page 158: Device Configuration

    268XA Service Manual An input line to the device consists of one or more semicolon-separated commands followed by an input terminator. The device will accept CR/LF or LF as the input terminator. The device reads input into a 350-byte input queue until it finds the input terminator.

  • Page 159: Command Set

    Diagnostic Testing and Troubleshooting Using the RS-232 Interface Table 6-6. Device Configuration Configuration Element Power-on Reset/Selftest Channel 1 to 20 configuration: Channel 1 only is V dc, function, range, terminals, TC type, Autorange RTD R0 Channel 1 to 20 OTC Channel 21 to 30 Equation Channel 1 to 30 Mx+B 1x+0...
  • Page 160 268XA Service Manual Table 6-7. RS-232 Command Set Command Description *IDN? Identification query *OPC? Operation complete query *RST Reset *TST? Self-test query SELFTEST? Return current self-test results Start calibration procedure for indicated function and input module CAL? Return the identifier of any cal procedure in progress Query the value of a particular calibration constant CAL_CONST? Specify value to calibrate to in place of default...
  • Page 161 Response: A description of data returned Restrictions: When the command is allowed/disallowed Notes: Any additional useful information Command: *IDN? Description: Identification query. Parameters: None Response: FLUKE, <model>, <serial-number>, <versions>, <module configuration> <model> = 2680A, 2686A <serial-number> = programmed serial number <versions> = YYYYMMDD 6-15...
  • Page 162 268XA Service Manual <module config> = 6 character string: “P” for PAI; “F” for FAI; “D” for DIO; “-“ for no module installed: ie, “PP-F-D” Restrictions: None Notes: None Command: *OPC? Description: Operation complete query. *OPC? causes 268XA to output an ASCII ‘1'. Parameters: None Response: <state>...
  • Page 163 Diagnostic Testing and Troubleshooting Using the RS-232 Interface Response: <self-test-result1>,<self-test-result2> = two integers which binary-encodes the self-test results as shown in Tables 6-1: self-test codes. Restrictions: Not allowed in calibration mode. Command: CAL Description: Initiate calibration procedure for the specified measurement function Parameters: <module number>, <procedure>...
  • Page 164 268XA Service Manual <module number> = integer 1 - 6 <cal constant number> = integer 0 - 60 (even integers only) Response: <value> = floating point calibration constant Restrictions: None Notes: The Calibration Constants section describes the calibration constants in detail. Command: CAL_REF Description: Specify value to calibrate to in place of default reference Parameters: <new calibration reference value>...
  • Page 165 Diagnostic Testing and Troubleshooting Using the RS-232 Interface This command returns an execution error if no cal procedure is active. This command returns a device dependent error if an internal error such as measurement timeout is detected. If the CAL_STEP? command completes successfully, the “calibrated value” returned is the reference value. If the command fails because the measured reading is outside of the specified limits, the raw measurement is returned.
  • Page 166 268XA Service Manual <range> may be specified for FREQ, but it is not used. a <range> value which is ‘na' in Table 6-8: Range Settings generates an execution error. Notes: On the 268XA PAI, channels 1 and 11 can measure 300V while the other channels can measure only 150V.
  • Page 167 Diagnostic Testing and Troubleshooting Using the RS-232 Interface When <function> is OHMS, <terminals> is always returned. When <function> is TC, response is “TC, AUTO, <thermocouple type>, <check OTC flag>” When <function> is RTD, response is “RTD, AUTO, <terminals>, <R0 value> [,alpha value]” When <function>...
  • Page 168 268XA Service Manual Command: DIO? Description: Get the value of the DIO Digital lines 0 through 19 Parameters: None Response: 0 to 1048575 (2^ – 1) Restrictions: None. Notes: 0: all lines low; 1: line 0 high, all other lines low; 2: line 1 high, all other lines low; 3: lines 0 and 1 high, all other lines low;...
  • Page 169 Diagnostic Testing and Troubleshooting Using the RS-232 Interface Restrictions: None. Notes: None. Command: TOT? Description: Get the value of the DIO Totalizer Parameters: None Response: 0 to 2^ (4,294,967,296) Restrictions: None. Notes: None. Command: TOTCFG <direction>, <debounce> Description: Set the value of the DIO Totalizer configuration Parameters: <direction>...
  • Page 170 268XA Service Manual Command: RATE? <module> Description: Get the scan speed Parameters: : <module> integer from 1 to 6 Response: FAST, MEDIUM, SLOW Restrictions: None. Notes: None. Command: SERIAL? <module> Description: Get the serial number for a module Parameters: <module> integer from 1 to 6 Response: programmed serial # Restrictions: None.

  • Page 171: Troubleshooting The Device

    For these cases, review Chapter 2 “Theory of Operation” and approach the difficulty in a logical manner adapting the troubleshooting procedures, as required. As a last resort, contact Fluke (see Chapter 7) for assistance.
  • Page 172 268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems Error Error Code Suspect Error Code Code Description Assembly Discussion Bad boot software Sys/Ctrl Background The System Power/Controller Board image in FLASH FLASH memory device, U20, is divided into sections. ROM.
  • Page 173 A2 Display PCA. Refer to paragraph “A2 Display PCA Troubleshooting. Module 1 Module Background Each module of the 2680A/2686A Calibration contains its own calibration constants on the A/D Power constants corrupt. daughter card. The A/D U7 FLASH memory device contains the calibration constants.
  • Page 174 Code Description Assembly Discussion Module 1 Module Background Each module of the 2680A/2686A Procedures contains its own calibration constants on the A/D Power Incomplete. daughter card. The A/D U7 FLASH memory device contains the calibration constants. The calibration constants are used by the A/D converter.
  • Page 175 Diagnostic Testing and Troubleshooting Troubleshooting the Device Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion Module 1 A3 A/D Background The A/D converters uses two very precise reference balance Converter voltages for operation: +3.45 V dc and -3.45 V dc.
  • Page 176 268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion Module 1 open A3 A/D Background The open thermocouple detect circuit thermocouple Converter checks on the amount of a 19.2 kHz voltage developed detect failed.
  • Page 177 Diagnostic Testing and Troubleshooting Troubleshooting the Device Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion RAM constants Sys/Ctrl Background The SYS/CTRL stores constants in flash corrupt. memory, U20, which are transferred to RAM for use in operation.
  • Page 178 268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion Module 2 open A3 A/D Background Same as for module 1. thermocouple Converter Failure Same as for module 1. detect failed.
  • Page 179 Diagnostic Testing and Troubleshooting Troubleshooting the Device Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion Module 4 A/D Module Background Same as for module 1. failure Failure Same as for module 1. Correction Same as for module 1.
  • Page 180 268XA Service Manual Table 6-9. Relating Selftest Errors to Device Problems (cont) Error Error Code Suspect Error Code Code Description Assembly Discussion Module 5 Module Background Same as for module 1. Overload Failure Same as for module 1. detection failed Correction Same as for module 1.
  • Page 181 Diagnostic Testing and Troubleshooting Troubleshooting the Device Table 6-10. Hints for Troubleshooting "Dead" Devices Possible Fault Discussion Blown Fuse If the device is completely dead, you may have blown the line fuse. There is also a fuse inline with the DC voltage input for battery input protection.

  • Page 182: Sys/Ctrl Pca Troubleshooting

    268XA Service Manual Sys/Ctrl PCA Troubleshooting The following paragraphs provide troubleshooting hints for the Sys/Ctrl PCA. Use this material in conjunction with Chapter 2, “Theory of Operation.” XWWarning To avoid electric shock, disconnect all power and channel inputs from the device before performing any troubleshooting operations.

  • Page 183: Troubleshooting The Ethernet Interface

    The following provides troubleshooting hints for the A2 Display PCA. Use this material in conjunction with Chapter 2, “Theory of Operation.” A Display Extender Cable is available from Fluke (PN 867952) for use during troubleshooting. XWWarning To avoid electric shock, disconnect all channel inputs from the device before performing any troubleshooting operations.

  • Page 184: Display Test Pattern #1

    268XA Service Manual Table 6-11. A2 Display PCA Initialization Routines A2TP4 DTEST* A2TP5 LTE* Power-Up Display Initialization All segments OFF All segments ON (default) Display Test Pattern #1 Display Test Pattern #2 Figures 6-1 and 6-2 show Display Test Patterns #1 and #2, respectively. REM SCAN SET FUNC REVIEW...

  • Page 185: Variations In The Display

    Diagnostic Testing and Troubleshooting Troubleshooting the Device 4. Check the state of the RESET signal (A2U1-1). This signal should be low once the reset time is completed (after power-up). Also verify that the RESET* signal (A2U6-3) is high after the reset time is completed. 5.

  • Page 186: Pcmcia Pca Troubleshooting

    12 V supply was designed to only provide enough power for the PCMCIA card, no other devices should be powered from this supply. This board plugs into P4 on the 2680A-4004 PCA. It is a daughter card that is only installed if the device is a 2686 chassis, as opposed to a 2680 chassis that has no PCMCIA option.

  • Page 187: Digital Input Buffers

    Diagnostic Testing and Troubleshooting Troubleshooting the Device Digital Input Buffers The Digital Input Threshold circuit sets the input threshold level for the Digital Input Buffers and the Totalizer Input. A fixed value voltage divider (R5, R6) and a unity gain buffer amplifier (U1) are the main components in the circuit.

  • Page 188: Totalizer Input

    Both problems can be troubleshot with a DMM. A3 A/D Converter Module Troubleshooting To access this card for test, the user may need the 2680A-7001K Extender kit, p.n. 1619174. The following paragraphs provide troubleshooting hints for the A3 A/D Converter PCA.

  • Page 189: Break/Reset Circuit

    Diagnostic Testing and Troubleshooting Troubleshooting the Device Table 6-12. A3 A/D Converter PCA Jumper Positions Jumper If Missing If in Place VBOOT enable at A3Q1 VBOOT disable at A3Q1 prevents (this jumper is in place when loading new A/D A3U6 from initializing (error 7 is firmware.

  • Page 190: Troubleshooting Relay Problems

    268XA Service Manual Troubleshooting Relay Problems Both the PAI and FAI use mechanical reed relays for signal switching, although the FAI uses solid-state relays for channel selection. The mechanical relays have a life of 100,000,000 operations. If you use your device in long-duration, high-speed measurement runs at high voltages and high common mode voltages, then the relays may start to act up after a few years.

  • Page 191: Retrieving Calibration Constants

    Diagnostic Testing and Troubleshooting Troubleshooting Calibration Failures Check the output of the calibration source. Does it equal the value called for by this calibration step? Check the calibration source. Is it in operate mode? Has it reverted to standby? If a calibration step has failed, the device remains on that step so that the output from the calibration source may be corrected or the calibration reference value (CAL_REF) being used by the device may be changed if it was improperly entered.
  • Page 192 268XA Service Manual Table 6-13. A/D Module Calibration Constants Maximum Constant Function Range Minimum Allowable Number Function Comment Allowable Value Value V dc 90 mV Gain +0.95000E+0 +1.05000E+0 V dc 90 mV Offset -0.00090E+0 +0.00090E+0 V dc 300 mV Gain +0.95000E+0 +1.05000E+0 V dc...

  • Page 193: Flukedaq Software

    These programs can be updated as required. If you would like to know if the software for your device is the most current, check the Fluke web pages under support, software downloads, and then data acquisition. At the time of this printing, the versions of code are as follows: main embedded code - 01_00.vxWorks,...
  • Page 194 268XA Service Manual 6-48...

  • Page 195: Replaceable Parts

    Chapter 7 Replaceable Parts Title Page Introduction ....................... 7-3 How to Obtain Parts ..................7-3 Service Centers....................7-3 Parts Lists ......................7-4...
  • Page 196 268XA Service Manual...

  • Page 197: Introduction

    How to Obtain Parts Electrical components may be ordered from the Fluke Corporations and its authorized representatives by using the part number designated in the replacement parts lists. To order parts directly from Fluke Corporation, call (toll-free) 1-800-526-4731. Outside the US, replacement parts can be ordered through your local service center.

  • Page 198: Parts Lists

    268XA Service Manual Parts Lists The following tables list the replaceable parts for the 268XA devices. Caution PCAs may be subject to damage by static discharge.
  • Page 199 Replaceable Parts Parts Lists Table 7-1. 2680A Final Assembly Parts List Part Reference Number Number Designator Description 109322 FUSE,FUSE,.25X1.25,0.5A,250V,SLOW 424416 A65MP9 HOLDER,HLDR,FUSE,1/4 X 1-1/4,LOPROFILE,PNLMT 1598923 2680A-4004 PCA, SYSTEM POWER AND CONTROLLER 295105 SCREW,SCREW,CAP,SCKT,SS,8-32,.375 109998 A65W1 5500A-4417,WIRE, BINDING POST TO FASTON...
  • Page 200 268XA Service Manual Table 7-1. 2680A Final Assembly Parts List (cont) Part Reference Number Number Designator Description 1560703 A63MP2 FLUKE 45-4021-01, ,ASSEMBLY DISPLAY 1593113 A63MP3-4 2680A-2021,HANDLE PLASTIC 8.75 IN. A65MP4-5 868786 A64MP9-12 5700A-2043-01,BOTTOM FOOT, MOLDED, GRAY #7 1593092 A63MP6 2680A-2019,FRONT BEZEL...
  • Page 201 Part Reference Number Number Designator Description 109322 FUSE,FUSE,.25X1.25,0.5A,250V,SLOW 424416 A65MP9 HOLDER,HLDR,FUSE,1/4 X 1-1/4,LOPROFILE,PNLMT 1598923 2680A-4004 PCA, SYSTEM POWER AND CONTROLLER 295105 SCREW,SCREW,CAP,SCKT,SS,8-32,.375 109998 A65W1 5500A-4417,WIRE, BINDING POST TO FASTON 1667870 2686A-8001,2686A FRONT PANEL DECAL 1598783 2680A-4001,PCA, BACK PLANE 284174 A99MP1 LC1 LINE CORD,NORTH AM,10A,5-15/IEC,18/3,SVT,7.5 FT...
  • Page 202 2680A-4041,PCA, PCMCIA INTERFACE 1778376 MEMORY CARD,FLASH,PC CARD,ATA TYPE II,16MB,CARD,BULK 1595629 CAPACITOR,ELECTROLYTIC,ALUMINUM,22000UF,+- 20%,50V,35X50 CASE WITH 4 LEADS,BULK 1606839 CAPACITOR,ELECTROLYTIC,ALUMINUM,470UF,+-20%,63V,LOW IMPEDANCE,12.5X30RADIAL,BULKPurchased Item 1631800 CONNECTOR,TERMINAL BLOCK,5MMCTR,SOCKET PLUG,8 POS,BULK 1623031 2680A-APSW,FLUKEDAQ - 2680 SOFTWARE - EXTRA COPY 1643733 2680A-4404,LINE FILTER / FUSE JUMPER 1282991 SCREW,M2,12MM,PAN,TORXPLUS,STEEL, ZINC-CHROMATE...
  • Page 203 Part Reference Number Number Designator Description 769422 LC3 LINE CORD,CONT EURO,10A,CEE-7/IEC,1MM/3,2.5M 1777348 CONNECTOR ACCESSORY,D-SUB JACK SCREW,4-40,.250 L,W/FLAT WASHER 172080 CABLE ACCESSORY,CABLE ACCESS,TIE,4.00L,.10W,.75 DIA 1777885 CABLE ASSEMBLY,8 COND,8 POS MOD PLUG EACH END,CAT5E CROSSOVER,RED,2M,BULK 871512 2620A-4406,T/C CABLE,ASSY 1631254 MANUAL,2680A/2686A GETTING STARTED...

  • Page 204: 268Xa Final Assembly

    268XA Service Manual alg105f.eps Figure 7-1. 268XA Final Assembly 7-10...

  • Page 205: Blank Module

    Replaceable Parts Parts Lists Table 7-3. Blank Module Parts List Part Reference Number Number Designator Description 1593050 2680A-2015, MODULE REAR PANEL 1669653 2680A-2013,BLANK MODULE BRACKET 1669889 2680A-8011,BLANK MODULE DECAL 2680A-BLANK alg101f.eps Figure 7-2. Blank Module 7-11...

  • Page 206: Dio Module

    268XA Service Manual Table 7-4. DIO Module Parts List Part Reference Number Number Designator Description 1598906 2680A-4006,PCA, DIGITAL IO AND RELAY 1593050 2680A-2015, MODULE REAR PANEL 152173 SCREW,6-32,.500,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 1593045 2680A-2011, FAI/PAI MODULE COVER 376822 SCREW,SCREW,PH,P,LOCK,SS,6-32,.750 1610886 2680A-2008, DIO MODULE BASE 152140 SCREW,6-32,.250,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK...
  • Page 207 Replaceable Parts Parts Lists 2680A-DIO alg100f.eps Figure 7-3. DIO Module 7-13...

  • Page 208: Fai Module

    152140 SCREW,6-32,.250,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 1593038 2680A-2010, FAI/PAI MODULE BASE 939723 A45MP203 2645A-4003M,A/D PWB ASSY (FFE) 757294 A45MP95-96 JUMPER,JUMPER,REC,2 POS,.100CTR,.025 SQ POST 1593197 2680A-4031, PCA, A/D POWER SUPPLY 949537 2620A-4004A,INPUT PWB ASSY,A4 698027 Y9XXX-8002,BAG, LARGE ACCESSORY 874107 2620A-2007,ISOTHERMAL CASE,BOTTOM 874110 2620A-2008,ISOTHERMAL CASE,TOP 1669892...
  • Page 209 Replaceable Parts Parts Lists 2680A-FAI alg102f.eps Figure 7-4. FAI Module 7-15...

  • Page 210: Pai Module

    2680A-2011, FAI/PAI MODULE COVER 376822 SCREW,SCREW,PH,P,LOCK,SS,6-32,.750 152140 SCREW,6-32,.250,PAN,PHILLIPS,STEEL,ZINC-CLEAR,LOCK 1593038 2680A-2010, FAI/PAI MODULE BASE 757294 A40MP95-96 JUMPER,JUMPER,REC,2 POS,.100CTR,.025 SQ POST 1593197 2680A-4031, PCA, A/D POWER SUPPLY 939744 A40MP260 2640A-2007,COVER, RELAYS 949537 2620A-4004A,INPUT PWB ASSY,A4 698027 Y9XXX-8002,BAG, LARGE ACCESSORY 874107 2620A-2007,ISOTHERMAL CASE,BOTTOM...
  • Page 211 Replaceable Parts Parts Lists 2680A-PAI alg103f.eps Figure 7-5. PAI Module 7-17...

  • Page 212: Isothermal Input

    Designator Description 949537 A04MP204 2620A-4004A,INPUT PWB ASSY,A4 698027 A14MP90 Y9XXX-8002,BAG, LARGE ACCESSORY 874107 A14MP2 2620A-2007,ISOTHERMAL CASE,BOTTOM 874110 A14MP3 2620A-2008,ISOTHERMAL CASE,TOP 1669892 2680A-8012,ISOTHERMAL CASE DECAL 876479 A14H65 SCREW,SCREW,KNURL,SL,CAPT,STL,6-32,.500 1259450 FACTORY BASE WARRANTY, 1 YEAR 2620A-180 alg104f.eps Figure 7-6. Isothermal Input 7-18...

  • Page 213: Figure Title Page

    Chapter 8 Schematics Figure Title Page 8-1. Backplane PCA...................... 8-3 8-2. Controller/System Power PCA ................8-5 8-3. Digital I/O PCA ..................... 8-11 8-4. Backplane Extender PCA ..................8-15 8-5. Extender PCA ......................8-17 8-6. A/D Supply Assembly ................... 8-19 8-7. PCMCIA PCA .......................
  • Page 214 268XA Service Manual...

  • Page 215: Backplane Pca

    Schematic Diagrams 2680A-4001 Figure 8-1. Backplane PCA...
  • Page 216 268XA Service Manual 2680A-1001 Figure 8-1. Backplane PCA (cont)

  • Page 217: Controller/System Power Pca

    Schematic Diagrams 2680A-4004 Figure 8-2. Controller/System Power PCA...
  • Page 218 J11,J12 N15,P4,P5 J13,J14 P15,P16 K6,K7,K8 R5,R6,R7 K9,K10 R8,R9,R10 K11,K12 R11,R12 K13,K14 R13,R14 L6,L7,L8 R15,T14 L9,L10 L11,L12 L13,L14 M6,M7,M8 M9,M10 M11,M12 M13,M14 N6,N7,N8 N9,N10 N11,N12 N13,N14 P6,P7,P8 P9,P10 P11,P12 P13,P14 240_AC 2680A-1004 (1 of 5) Figure 8-2. Controller/System Power PCA (cont)
  • Page 219 C119 180P NDS351AN 180P 180P 0.1U 5233 AMD1385ARS 70 OHM 0.1U 70 OHM 70 OHM C150 0.1U C149 70 OHM 70 OHM C148 0.1U CONSOLE RS232 PORT 0.1U DEVEL ONLY 2680A-1004 (2 of 5) Figure 8-2. Controller/System Power PCA (cont)
  • Page 220 WAIT* R139 CE2* 2.49K VPEN CS0* TP55 WE0* R136 BUF_DATA<0..15> 74LCX16245 TP57 10.0K TP58 HRESET* TP59 R_W* TP60 BYTE TP61 7S04 C156 TP62 0.1U R137 TP80 10.0K CE1* PCMCIA INTERFACE 2680A-1004 (3 of 5) Figure 8-2. Controller/System Power PCA (cont)
  • Page 221 I/O-92 I/O-196 GUARDCK0 TP47 I/O-93 I/O-197 GUARDCK0* TP48 I/O-94 I/O-198 GUARDCK1 TP49 I/O-95 I/O-199 GUARDCK1* TP50 I/O-96 I/O-200 FIL_CLK TP51 I/O-97 I/O-202 FIL_CLK* TP52 I/O-99 I/O-203 TP56 I/O-100 I/O-205 ADDR<6..31> 2680A-1004 (4 of 5) Figure 8-2. Controller/System Power PCA (cont)
  • Page 222 DECOUPLING FOR U2 - U5, U10 - U12, 1 CAP PER POWER PIN C133 C134 C117 C165 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 0.01U 2680A-1004 (5 of 5) Figure 8-2. Controller/System Power PCA (cont) 8-10...

  • Page 223: Digital I/O Pca

    Schematic Diagrams 2680A-4006 Figure 8-3. Digital I/O PCA 8-11...
  • Page 224 268XA Service Manual 2680A-1006 (1 of 3) Figure 8-3. Digital I/O PCA (cont) 8-12...
  • Page 225 Schematic Diagrams 2680A-1006 (2 of 3) Figure 8-3. Digital I/O PCA (cont) 8-13...
  • Page 226 268XA Service Manual 2680A-1006 (3 of 3) Figure 8-3. Digital I/O PCA (cont) 8-14...

  • Page 227: Backplane Extender Pca

    Schematic Diagrams 2680A-4009 Figure 8-4. Backplane Extender PCA 8-15...
  • Page 228 268XA Service Manual 2680A-1009 Figure 8-4. Backplane Extender PCA (cont) 8-16...

  • Page 229: Extender Pca

    Schematic Diagrams 2680A-4010 Figure 8-5. Extender PCA 8-17...
  • Page 230 268XA Service Manual 2680A-3010 Figure 8-5. Extender PCA (cont) 8-18...

  • Page 231: A/D Supply Assembly

    Schematic Diagrams 2680A-4031 Figure 8-6. A/D Supply Assembly 8-19...
  • Page 232 268XA Service Manual 2680-1031 Figure 8-6. A/D Supply Assembly (cont) 8-20...

  • Page 233: Pcmcia Pca

    Schematic Diagrams 2680A-4041 Figure 8-7. PCMCIA PCA 8-21...
  • Page 234 268XA Service Manual 2686-1041 Figure 8-7. PCMCIA PCA (cont) 8-22...

  • Page 235: Output Pca

    Schematic Diagrams 2680A-4062 Figure 8-8. Output PCA 8-23...
  • Page 236 268XA Service Manual 2680A-1062 Figure 8-8. Output PCA (cont) 8-24...
  • Page 237 Schematic Diagrams 2640A-4003 Figure 8-9. A/D (PFE) PCA 8-25...
  • Page 238 268XA Service Manual (1 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-26...
  • Page 239 Schematic Diagrams (2 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-27...
  • Page 240 268XA Service Manual 2640A-1003 (3 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-28...
  • Page 241 Schematic Diagrams 2640A-1003 (4 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-29...
  • Page 242 268XA Service Manual 2640A-1003 (5 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-30...
  • Page 243 Schematic Diagrams 2640A-1003 (6 of 6) Figure 8-9. A/D (PFE) PCA (cont) 8-31...
  • Page 244 268XA Service Manual 2645A-4003 Figure 8-10. A/D (FFE) PCA 8-32...
  • Page 245 Schematic Diagrams 2645A-1003 (1 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-33...
  • Page 246 268XA Service Manual 2645A-1003 (2 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-34...
  • Page 247 Schematic Diagrams 2645A-1003 (3 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-35...
  • Page 248 268XA Service Manual 2645A-1003 (4 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-36...
  • Page 249 Schematic Diagrams 2645A-1003 (5 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-37...
  • Page 250 268XA Service Manual 2645A-1003 700p29_topress.zip (6 of 6) Figure 8-10. A/D (FFE) PCA (cont) 8-38...

  • Page 251: Analog Input Connector Pca

    Schematic Diagrams 2620A-4004A Figure 8-11. Analog Input Connector PCA 8-39...
  • Page 252 268XA Service Manual 2620A-1004 Figure 8-11. Analog Input Connector PCA (cont) 8-40...

  • Page 253: Display Pca

    Schematic Diagrams (1 of 1) Figure 8-12. Display PCA 8-41...
  • Page 254 268XA Service Manual (1 of 1) Figure 8-12. Display PCA (cont) 8-42...

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