1. Manuals
  2. Brands
  3. NI Manuals
  4. Multiplexer
  5. 2501
  6. User manual

NI 2501 User Manual

24-channel two-wire multiplexer
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Computer-Based
Instruments
NI 2501/2503 User Manual
24-Channel Two-Wire Multiplexer
NI 2501/2503 User Manual
June 1998 Edition
Part Number 321906A-01

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 2501 and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for NI 2501

Summary of Contents for NI 2501

  • Page 1 Computer-Based Instruments NI 2501/2503 User Manual 24-Channel Two-Wire Multiplexer NI 2501/2503 User Manual June 1998 Edition Part Number 321906A-01...
  • Page 2 Internet Support E-mail: support@natinst.com FTP Site: ftp.natinst.com Web Address: http://www.natinst.com Bulletin Board Support BBS United States: 512 794 5422 BBS United Kingdom: 01635 551422 BBS France: 01 48 65 15 59 Fax-on-Demand Support 512 418 1111 Telephone Support (USA) Tel: 512 795 8248 Fax: 512 794 5678 International Offices Australia 03 9879 5166, Austria 0662 45 79 90 0, Belgium 02 757 00 20, Brazil 011 288 3336,...
  • Page 3 Warranty The NI 2501 and NI 2503 are warranted against defects in materials and workmanship for a period of one year from the date of shipment, as evidenced by receipts or other documentation. National Instruments will, at its option, repair or replace equipment that proves to be defective during the warranty period.
  • Page 4 Compliance FCC/DOC Radio Frequency Interference Class A Compliance This equipment generates and uses radio frequency energy and, if not installed and used in strict accordance with the instructions in this manual, may cause interference to radio and television reception. Classification requirements are the same for the Federal Communications Commission (FCC) and the Canadian Department of Communications (DOC).
  • Page 5 Conventions The following conventions are used in this manual. < > Angle brackets containing numbers separated by an ellipsis represent a range of values associated with a port, bit, or signal name (for example, ACH<0..7> stands for the signals ACH0 through ACH7). This icon to the left of bold italicized text denotes a note, which alerts you to important information.

  • Page 6: Table Of Contents

    Contents Chapter 1 Routing Signals with Your NI 2501/2503 About the NI 2501/2503 ....................1-1 Analog Bus ......................1-2 Triggers......................1-2 Cold-Junction Sensor Channel ................1-3 NI 2501 Amplifier ...................1-3 Connecting Signals ......................1-4 Front Connector....................1-4 Contact Protection......................1-8 Terminal Blocks......................1-9 Software Choices ......................1-9 NI-SWITCH Driver Software .................1-9 National Instruments Application Software ............1-9...
  • Page 7 Front Connector Pinout Assignments for One-Wire Mode ....1-6 Figure 1-3. Front Connector Pinout Assignments for Four-Wire Mode ....1-7 Figure 2-1. NI 2501 Module Block Diagram ............2-2 Figure 2-2. NI 2503 Module Block Diagram ............2-3 Figure C-1.

  • Page 8: Routing Signals With Your Ni 2501/2503

    Instruments NI-SWITCH software included with your kit to configure and operate the NI 2501/2503 switch card. The NI 2501/2503 can also operate as two 12 x 1 or four 6 x 1 two-wire multiplexers. You can use software-configurable switches to configure the switch card as a 48 x 1 one-wire multiplexer for making large numbers of common referenced measurements.

  • Page 9: Analog Bus

    The triggers can be routed to the front connector of the NI 2501/2503, to any of the PXI TTL triggers, or to the PXI star trigger. If no external trigger input is available, you can have the software trigger the NI 2501/2503 to advance to the next entry in the scan list.

  • Page 10: Cold-Junction Sensor Channel

    NI 2501 Amplifier The NI 2501 has an amplifier with a gain of 1. This amplifier can be switched in-line before the COM0 signal and the AB0 signal. The amplifier helps to decrease the settling time of the FET switch. The amplifier’s high impedance isolates the FET from the resistance, capacitance, and inductance in the external wiring.

  • Page 11: Connecting Signals

    Routing Signals with Your NI 2501/2503 Connecting Signals This section describes the signal connections to the NI 2501/2503 module via the module front connector. This section also includes specifications and connection instructions for the signals on the NI 2501/2503 module connectors.

  • Page 12: Figure 1-1. Front Connector Pinout Assignments For Two-Wire Mode

    Chapter 1 Routing Signals with Your NI 2501/2503 34 68 CJS0- CJS0+ CH0- 33 67 CH0+ CH1- 32 66 CH1+ CH2- 31 65 CH2+ 30 64 CH3- CH3+ CH4- 29 63 CH4+ CH5- 28 62 CH5+ COM0- 27 61 COM0+...

  • Page 13: Figure 1-2. Front Connector Pinout Assignments For One-Wire Mode

    Chapter 1 Routing Signals with Your NI 2501/2503 34 68 CJS- CJS+ CH24 33 67 CH25 32 66 CH26 31 65 30 64 CH27 CH28 29 63 CH29 28 62 COM0- 27 61 COM0+ COM1- (CH30-CH35) 26 60 COM1+ (CH6-CH11)

  • Page 14: Figure 1-3. Front Connector Pinout Assignments For Four-Wire Mode

    Any connections that exceed the maximum settings for the NI 2501/2503 can result in an electrical shock hazard and damage to the NI 2501/2503 module and any or all of the boards connected to the PXI backplane. National Instruments is liable for any damages or injuries resulting from exceeding maximum voltage ratings.

  • Page 15: Contact Protection

    Chapter 1 Routing Signals with Your NI 2501/2503 Table 1-1. Front Connector Signal Description Signal Name Type Description +5 V Output +5 VDC Source—Powers the temperature sensor on the terminal block. 0.2 mA of source protected by a resettable poly fuse.

  • Page 16: Terminal Blocks

    Routing Signals with Your NI 2501/2503 Terminal Blocks Several terminal blocks with screw terminals are available for easy signal connection to the NI 2501/2503 inputs. Refer to Appendix B, Accessories. Software Choices You have several options to choose from when programming your National Instruments switch card.

  • Page 17: Third Party Software

    Routing Signals with Your NI 2501/2503 LabWindows/CVI features interactive graphics, a state-of-the-art user interface, and uses the ANSI standard C programming language. The LabWindows/CVI NI-SWITCH Library, a series of functions for using LabWindows/CVI with National Instruments switch hardware, is included with the NI-SWITCH driver.

  • Page 18: Ni 2501/2503 Operation

    Functional Overview The block diagrams on the following pages illustrate the key functional components of the switch card modules. Figure 2-1 shows the NI 2501 and Figure 2-2 shows the NI 2503. The major components of the NI 2501/2503 modules are as follows: •...

  • Page 19: Figure 2-1. Ni 2501 Module Block Diagram

    Com0 One Wire / Two Wire Select Unity Gain Amplifier Select AISENSE Cold Junction Sensor Com1 CH11 Analog Bus1 Com2 CH12 CH17 Com3 CH18 CH23 Figure 2-1. NI 2501 Module Block Diagram NI 2501/2503 User Manual © National Instruments Corporation...

  • Page 20: Figure 2-2. Ni 2503 Module Block Diagram

    NI 2501/2503 Operation Analog Bus0 Com0 One Wire / Two Wire Select AISENSE Cold Junction Sensor Com1 CH11 Analog Bus1 Com2 CH12 CH17 Com3 CH18 CH23 Figure 2-2. NI 2503 Module Block Diagram © National Instruments Corporation NI 2501/2503 User Manual...

  • Page 21: Multiplexer

    Architecture Drawings, for illustrations of the NI 2501 and NI 2503 architecture. The NI 2503 relays are single-side stable. When power is removed from the relay coil, the relay returns to its de-energized state. The de-energized state opens all the relays, disconnecting the device from external inputs and outputs.

  • Page 22: Four-Wire

    Switch Control Circuitry The switch control circuitry (SCC) is responsible for opening and closing FET switches on the NI 2501 or relays on the NI 2503. You can load commands for the SCC into memory storage using the driver software you received with your kit.

  • Page 23: Pxi Interface

    The NI 2501/2503 switch card has a PXI interface through which you can use your driver software to configure and control the card. The NI 2501/2503 takes advantage of PXI features. It uses the PXI TTL triggers to synchronize scanning with a measurement device such as a National Instruments NI-4060 PXI digital multimeter (DMM).

  • Page 24: Scanner Advanced

    (or debounced). All SCANADV trigger lines are compatible with TTL voltage levels. Because the NI 2501/2503 has open collector drives on the PXI TTL trigger lines, you can have multiple switch cards using the same trigger line in the multicard SCANADV mode.

  • Page 25: Multicard Triggering

    Always configure the triggers in a system before configuring the measurement device or the NI 2501/2503 for scanning. When triggers are configured, a state change or pulse could occur on the trigger line. This is also possible when you reset the switch card.
  • Page 26 Specifications This appendix lists the specifications for the NI 2501 and NI 2503 switch cards. These specifications are typical at 25° C unless otherwise noted. NI 2501 Input Characteristics Number of Channels ......24 Maximum Working Voltage ....± 10 VDC from chassis ground Overvoltage Protection Signals CH<0..23>, COM<0..3>...
  • Page 27 Appendix A Specifications for NI 2501 Transfer Characteristics Channel Amplifier (Unity Gain) Offset Voltage (Differential) ....1.2 mV max Cold-Junction Sensor Channel Amplifier (Unity Gain) Offset Voltage Maximum ........60 µV Frequency Bandwidth (50 Ω source, 1 MΩ 25 pF load) –3 dB ..........400 KHz –10 dB ..........1 MHz...
  • Page 28 Appendix A Specifications for NI 2501 0.006% Accuracy With output buffer selected ..30 µs Without output buffer ....60 µs 0.0015% Accuracy With output buffer selected ..80 µs Without output buffer ....160 µs Note Settling time is greatly affected by the external wiring to the switch card. You can improve the settling time by minimizing the wiring from the analog bus connection to the measurement device.
  • Page 29 Appendix A Specifications for NI 2501 Environment Operating Temperature ......0° to 50° C Storage Temperature......–55° to 150° C Relative Humidity........5% to 90% non-condensing Shock and Vibration Functional Shock MIL-T-28800E Class 3 (30 g half sine shock pulse) Also meets IEC 60068-2-27...
  • Page 30 Differential Channel or Single ended..60 VA, 30 W Contact on Resistance (Initial)....100 mΩ Contact Material........Gold-clad Silver Alloy Transfer Characteristics Thermal E.M.F. (Differential)....<2 µV Maximum Frequency Bandwidth 50 Ω Termination Worst case channel ......35 MHz © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 31 Mechanical (@ 180 cpm) ....5 × 10 operations Electrical at Maximum Load ...2 × 10 operations PXI Bus Interface Slave PXI Trigger Bus Trigger Lines ..........8 Star Trigger..........1 Power Requirement +5 V Typical..........370 mA Maximum ........700 mA NI 2501/2503 User Manual © National Instruments Corporation...
  • Page 32 MIL-T-28800E Class 3 (30 g half sine shock pulse) Also meets IEC 60068-2-27 Random Vibration MIL-T-28800E, MIL-STD-810E Category 1 Operational ......5 to 500 Hz, 0.3 grams Non-operational ....... 5 to 500 Hz, 2.4 grams Product Compliance IEC-1010, UL311, CE © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 33 This is connected to the switch card through the SH68-68S cable. • SH68-68S shielded 68-conductor cable connects the NI 2501/2503 to the TBX-68S, or TBX-68LP. Contact National Instruments for more specific information about these products.
  • Page 34 Customizing Your Card This appendix describes options for customizing your NI 2501/2503 card. Current-Loop Receivers The NI 2501/2503 modules have sockets for transforming individual channels to current-to-voltage converters. National Instruments offers a process-current pack of four 249 Ω, 0.1%, 5 ppm, 0.25 W resistors.

  • Page 35: Figure C-1. Bent And Trimmed Resistor

    Appendix C Customizing Your Card Figure C-1. Bent and Trimmed Resistor NI 2501/2503 User Manual © National Instruments Corporation...

  • Page 36: Front Connector Pinout Assignments For One-Wire Mode

    1-WIRE. • For the relay that switches CHx+ or CHx– to COM0+, the name is H/L SEL. • For the Amp Select switches (NI 2501 only), the names are AMP0 and AMP1. © National Instruments Corporation NI 2501/2503 User Manual...

  • Page 37: Figure D-1. Ni 2501 Switch Architecture

    CH13– CH14+ CH14– Bank2 CH15+ CH15– CH16+ CH16– CH17+ CH17– BC2-3 CH18+ COM3+ CH18– COM3– CH19+ CH19– CH20+ CH20– Bank3 CH21+ CH21– CH22+ CH22– CH23+ CH23– Figure D-1. NI 2501 Switch Architecture NI 2501/2503 User Manual © National Instruments Corporation...

  • Page 38: Figure D-2. Ni 2503 Switch Architecture

    CH13– CH14+ CH14– Bank2 CH15+ CH15– CH16+ CH16– CH17+ CH17– BC2-3 CH18+ COM3+ CH18– COM3– CH19+ CH19– CH20+ CH20– Bank3 CH21+ CH21– CH22+ CH22– CH23+ CH23– Figure D-2. NI 2503 Switch Architecture © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 39 The default debounce time for the NI 2503 switch card is set to just under 5 ms. This setting allows the card to be scanned at 200 scans/s. However, if the software implements break-before-make, this would reduce the scan rate to 100 scans/s.
  • Page 40 DMM to start taking measurements. • Also be sure to check the return codes of the NI-SWITCH operation to ensure that there are no errors (negative value) or warnings (positive value). You can also use the NI-Spy utility to check for error codes.
  • Page 41 To access our FTP site, log on to our Internet host, , as and use ftp.natinst.com anonymous your Internet address, such as , as your password. The support files and joesmith@anywhere.com documents are located in the directories. /support © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 42 08 730 43 70 Switzerland 056 200 51 51 056 200 51 55 Taiwan 02 377 1200 02 737 4644 United Kingdom 01635 523545 01635 523154 United States 512 795 8248 512 794 5678 NI 2501/2503 User Manual © National Instruments Corporation...
  • Page 43 Technical Support Form Photocopy this form and update it each time you make changes to your software or hardware, and use the completed copy of this form as a reference for your current configuration. Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently.
  • Page 44 Completing this form accurately before contacting National Instruments for technical support helps our applications engineers answer your questions more efficiently. National Instruments Products Using NI 2501 or NI 2503?_________________________________________________________ Hardware revision ________________________________________________________________ Switching mode__________________________________________________________________ List National Instruments Software Installed and Version...
  • Page 45 List All Boards in PXI Mainframe PXI Slot Manufacturer, Description, and Function...
  • Page 46 Documentation Comment Form National Instruments encourages you to comment on the documentation supplied with our products. This information helps us provide quality products to meet your needs. Title: NI 2501/2503 User Manual Edition Date: June 1998 Part Number: 321906A-01 Please comment on the completeness, clarity, and organization of the manual.
  • Page 47 American National Standards Institute breakpoint a specified point in program code where the program pauses to perform some action; a breakpoint interrupt can be added to a scan list for debugging or other special needs. © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 48 DMA is the fastest method of transferring data to/from computer memory. See digital multimeter. drivers/driver software software that controls a specific hardware device such as a switch card NI 2501/2503 User Manual © National Instruments Corporation...
  • Page 49 See Intelligent Virtual Instrument. megabytes of memory matrix superset of multiplexer; consists of connected rows and columns that allows for a direct connection from any row to any column movistor transient suppression device © National Instruments Corporation NI 2501/2503 User Manual...
  • Page 50 Typically, the measurement device uses a trigger to advance the multiplexer to the next channel in the scan. scan list a list of channels supplied to NI-SWITCH that indicates the order in which channels will be scanned NI 2501/2503 User Manual...
  • Page 51 NI-SWITCH that you can use to interactively control the switch Terminal Block Extension terminal block...
  • Page 52 Glossary watts wire data path between nodes NI 2501/2503 User Manual © National Instruments Corporation...
  • Page 53 Index Numbers current-loop receivers, C1 to C-2 customer communication, F-1 to F-2 1_WIRE_LO_REF signal (table), 1-8 customizing NI 2501/2503, C1 to C-2 +5 V signal (table), 1-8 debounced switches, 1-2 AB<0..1>± signal (table), 1-8 dynamic characteristics AB<0..1>_SENSE± signal (table), 1-8...
  • Page 54 NI-SWITCH driver software, 1-9, E-1 to E-2 I/O connector blocks TBX-68LP, B-1 TBX-68S, B-1 one-wire multiplexer, 2-3 operation of NI 2501/2503, 2-1 to 2-8 block diagrams LabVIEW software, 1-9 NI 2501 module, 2-2 LabWindows/CVI software, 1-9 to 1-10 NI 2503 module, 2-3...
  • Page 55 NI 2501, A-3 NI-SWITCH driver software, 1-9 NI 2503, A-6 specifications PXI-TB-2605 terminal block, B-1 NI 2501, A-1 to A-4 PXI-TB-2606 terminal block, B-1 dynamic characteristics, A-2 to A-3 environment, A-4 input characteristics, A-1 questions and answers, E-1 to E-2...
  • Page 56 F-2 terminal blocks analog bus connectors, B-1 voltage availability, 1-9 flyback voltages (caution), 1-8 PXI-TB-2605, B-1 maximum voltage (note), 1-2 PXI-TB-2606, B-1 transfer characteristics NI 2501, A-2 NI 2503, A-6 NI 2501/2503 User Manual © National Instruments Corporation...

This manual is also suitable for:

2503

Table of Contents