Ruska Instrument 7252 User Manual

Ruska Instrument 7252 User Manual

Digital pressure controller
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DIGITAL PRESSURE CONTROLLER
MODEL 7252
i
MODEL 7252
USER'S MANUAL
RUSKA INSTRUMENT CORPORATION
10311 WESTPARK DR., HOUSTON, TEXAS 77042
(713) 975-0547 FAX: (713) 975-6338
e-mail:
ruska@ruska.com
http://www.Ruska.com
Release: 7252-1D01
Revision: A
Date: 09/16/03

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Summary of Contents for Ruska Instrument 7252

  • Page 1 DIGITAL PRESSURE CONTROLLER MODEL 7252 MODEL 7252 USER’S MANUAL RUSKA INSTRUMENT CORPORATION 10311 WESTPARK DR., HOUSTON, TEXAS 77042 (713) 975-0547 FAX: (713) 975-6338 e-mail: ruska@ruska.com http://www.Ruska.com Release: 7252-1D01 Revision: A Date: 09/16/03...
  • Page 2 WARRANTY Ruska Instrument Corporation warrants its products to conform to or exceed the specifications as set forth in its catalogs in use at the time of sale and reserves the right, at its own discretion, without notice and without making similar changes in articles previously manufactured, to make changes in materials, designs, finish, or specifications.
  • Page 3: Copyright Notice

    COPYRIGHT NOTICE Copyright © 1997 by Ruska Instrument Corporation. All rights reserved. This document may not be reproduced in part or in whole without the express written consent of Ruska Instrument Corporation. DISCLAIMER No representations or warranties are made with respect to the contents of this user’s manual.
  • Page 4: Revision Notice

    REVISION NOTICE RELEASE REV. DATE OF DESCRIPTION NUMBER RELEASE 7252-1D01 09/16/03 Original release. See DC/RO 23958. -iv- INTRODUCTION...
  • Page 5: Revision History

    REVISION HISTORY RELEASE 7252-1D01 Revision A (09/16/03) Original release See DC/RO 23958. INTRODUCTION...
  • Page 6 7252 – Change Language mode Hold key for 5 seconds enter -vi- INTRODUCTION...
  • Page 7: Safety Summary

    SAFETY SUMMARY The following are general safety precautions that are not related to any specific procedures and do not appear elsewhere in this publication. These are recommended precautions that personnel must understand and apply during equipment operation and maintenance to ensure safety and health and protection of property. KEEP AWAY FROM LIVE CIRCUITS Operating personnel must at all times observe safety regulations.
  • Page 8: Table Of Contents

    TABLE OF CONTENTS WARRANTY ......................-ii- COPYRIGHT NOTICE .................... -iii- REVISION NOTICE ....................-iv- REVISION HISTORY....................-v- CHANGE LANGUAGE................... -vi- SAFETY SUMMARY ....................-vii- TABLE OF CONTENTS ..................-viii- SECTION 1.0: GENERAL INFORMATION INTRODUCTION................1-1 GENERAL INFORMATION ..............1-1 FEATURES ..................1-1 STANDARD EQUIPMENT & OPTIONS ..........1-3 SECTION 2.0: THEORY OF OPERATION INTRODUCTION................2-1 POWER SUPPLY.................2-2...
  • Page 9 2.6.2 SENSOR BOARD..............2-11 2.6.3 LINEARIZATION TERM.............2-11 2.6.4 AUXILIARY SENSORS...............2-12 2.6.4.1 Case Reference Vacuum Sensor - Option ....2-12 SOFTWARE ...................2-12 2.7.1 SOFTWARE SAFETY CONTROLS ..........2-12 2.7.1.1 Preventing Operator Errors .........2-12 2.7.1.2 Pneumatic Errors............2-12 2.7.1.3 Shutoffs ..............2-12 2.7.1.4 Oven Control ............2-12 2.7.1.5 Pressure Reading and Correction ........2-13 SECTION 3.0: INSTALLATION INTRODUCTION................3-1 UNPACKING THE DPC ..............3-1...
  • Page 10 4.6.1.1.1 High Limit ............4-10 4.6.1.1.2 Low Limit............4-11 4.6.1.1.3 Auto Vent .............4-11 4.6.1.1.4 Control Band..........4-11 4.6.1.1.5 Control ............4-12 4.6.1.1.6 Slew Rate .............4-12 4.6.1.1.7 Slew Limit .............4-12 4.6.1.1.8 Access............4-12 4.6.1.2 Menu | Setup - User...........4-12 4.6.1.2.1 Step Size ............4-13 4.6.1.2.2 Bar Graph Maximum ........4-13 4.6.1.2.3 Ready Tolerance ...........4-13 4.6.1.2.4 Gas Head Pressure Correction.......4-13 4.6.1.2.5 Atmosphere..........4-14...
  • Page 11 5.4.5 EXAMPLE SCPI COMMANDS .............5-8 5.4.6 SCPI STATUS REGISTERS ............5-9 SERIAL OPERATION ................5-11 SAMPLE PROGRAMS ...............5-11 5.6.1 SAMPLE PROGRAM 1 - 7252 GPIB (IEEE-488) - CONTROLS PRESSURE TO 20.000%FS ............5-11 5.6.2 SAMPLE PROGRAM 2 - 7252 GPIB (IEEE-488) - ZERO SEQUENCE ................5-13 5.6.3 SAMPLE PROGRAM 3 - 7252 SERIAL (RS-232) - CONTROLS...
  • Page 12 FIGURE 2-1: DPC BLOCK DIAGRAM ...............2-1 FIGURE 2-2A MODEL 7252 DPC GAUGE PNEUMATICS DIAGRAM ......2-4 FIGURE 2-2B MODEL 7252 DPC ABSOLUTE PNEUMATICS DIAGRAM TO 50 PSIA ..2-5 FIGURE 2-3: PRESSURE CONTROL NORMAL MODE ..........2-9 FIGURE 2-4: PRESSURE CONTROL FAST MODE............2-9 FIGURE 2-5: SHAFT/MAGNET SECTION..............2-10...
  • Page 13: Section 1.0: General Information

    It is also used to monitor barometric pressures, vacuum systems, and differential pressure devices. The 7252 has two full scale pressure ranges and two pressure controllers integrated into one instrument. FEATURES The following features are available on all Model 7252 DPC’s.
  • Page 14 how close the actual pressure is to the commanded pressure, as well as how close the commanded pressure is to the DPC’s full scale pressure. Friendly Display: The DPC’s color active matrix TFT display combines a bright, low- glare readout with a wide viewing angle. During normal operation, the measured pressure is easily visible from a distance of 10 feet (3 meters).
  • Page 15: Standard Equipment & Options

    Table 1-1. To order these items, please contact Ruska Instrument Sales in the U.S. at (713) 975-0547. TABLE 1-1 OPTIONS LIST FOR THE MODEL 7252 DPC Option Ruska Instrument Corp. Part Number (RIC #) LabView Driver (National Instruments)
  • Page 16 NOTES INTRODUCTION...
  • Page 17: Introduction

    This section of the manual describes the DPC’s component modules (Figure 2–1) and provides a general discussion of each. The 7252 has two pneumatic control and two primary transducer modules. Primary Transducer Module 2...
  • Page 18: Power Supply

    The DPC’s universal power supply accepts AC voltages from 90 to 260 volts at 47-63 Hz. and DC voltages from 100 to 370 volts. This quad–output supply produces +5 VDC, +/-12 VDC, and 24 VDC which are distributed to the Control and Backplane Boards. ELECTRONICS MODULE 2.3.1 BACK-PLANE BOARD...
  • Page 19: Digital Control Board

    TABLE 2–1 CONVERSION FACTORS Unless specified otherwise, conversion factors are based on ANSI 268–1982. Symbol Description Conversion Factor InHg inches of mercury (0 °C) = kPa x 0.2952998 InHg inches of mercury (60 °F) = kPa x 0.296134 KiloPascals = kPa x 1.0 Bars = kPa x 0.01 pounds per square inch...
  • Page 20: Pneumatics Module

    Control Section PRIMARY SENSOR VACUUM SENSOR Option FIGURE 2–2A MODEL 7252 DPC GAUGE PNEUMATICS DIAGRAM 0.36 to 2500 psig (2.5 kPa to 17.2 MPa) Full Scale Ranges Note, this diagram depicts only one of the two 7252 channels. THEORY OF OPERATION...
  • Page 21: Measure Mode Pneumatics

    INNER LOOP CONTROL SENSOR Control Section PRIMARY SENSOR VACUUM SENSOR Option FIGURE 2–2B MODEL 7252 DPC ABSOLUTE PNEUMATICS DIAGRAM TO 50 PSIA (340 kPa) FS Note, this diagram depicts only one of the two 7252 channels. Valve Measure Mode Vent Control Mode Zeroing...
  • Page 22: Barometric Sensor

    Gauge mode DPC to function in a Absolute system. A 7252 must have a minimum full scale pressure range of 14.7 psig (101 kPa) in order to be configured to operate in the simulated absolute mode using the barometric reference sensor.
  • Page 23: Vent Procedure

    Module. Please refer to Appendix A for gas specifications and supply pressure limits. On the 7252, there are two supply pressure ports, one for each channel. A separate regulated pressure supply will need to be connected to each individual supply pressure ports.
  • Page 24: Pressure Control

    2.4.2.3 Pressure Control Pressure control is performed by a dual-loop control system. The inner loop is a digital loop using a high frequency response silicon strain gauge sensor, a digital controller, and two pulse-width modulated solenoids. The two solenoids either add gas to the test port or remove it.
  • Page 25: Pid Control

    2.5.5 PID CONTROL The outer loop pressure controller is a form of PID control executed every 100 milliseconds (10 times per second). The pressure is controlled to an exponential decay curve. ∫ − − − A dt d S = Set-point A = Actual V = Control Output p,i,d = Control Coefficients...
  • Page 26: Transducer Module

    TRANSDUCER MODULE 2.6.1 QUARTZ BOURDON TUBE SENSOR (TRANSDUCER01) The quartz Bourdon tube sensor is mounted in a machined aluminum housing. The sensor consists of a helical quartz tube with a mirror affixed to one end, as shown in Figure 2-5. A rigid beam is attached transverse to the axis of the helical tube.
  • Page 27: Sensor Board

    FIGURE 2–6 PHOTOCELL/LIGHT SPOT 2.6.2 SENSOR BOARD A temperature sensor and the quartz Bourdon tube pressure sensor are monitored by the Sensor Board. The Sensor board is also used to control and maintain the sensor housing at 50°C. 2.6.3 LINEARIZATION TERM As described in the previous section, the relationship between the pressure being measured and the current required to keep the quartz Bourdon tube in its zero position is the main principle behind the operation of the DPC’s sensing element.
  • Page 28: Auxiliary Sensors

    2.6.4 AUXILIARY SENSORS Auxiliary sensors are sensors such as the oven temperature sensor. These are reference sensors aligned at the factory and are utilized by the firmware. 2.6.4.1 Case Reference Vacuum Sensor - Option A case reference vacuum sensor is a user selectable option. This option includes a vacuum sensor installed into the test port on absolute units and the sensor case reference port on differential units and can be read directly by the DPC.
  • Page 29: Pressure Reading And Correction

    viewing the MENU | DISPLAY screen and verifying that the temperature is at 50 C. In addition to the temperature, this screen will show the duty cycle of the oven. When operating the system in either a very cold or hot environment, if the oven in unable to maintain the temperature of the internal oven, the DPC will generate an Oven Control Failure error messages.
  • Page 30 The following equations are used by the control algorithm to adjust and correct the pressure signal. Zero Coefficients Zero correction for High FSR (Full-Scale Resistors) Value is in counts (7,381,975 = full scale of current sensor). Zero correction for Low FSR. Value is in counts (7,381,975 = full scale of low FSR) Hardware zero correction.
  • Page 31: Section 3.0: Installation

    SECTION 3.0 INSTALLATION INTRODUCTION This section of the manual discusses initial installation for the Model 7252 DPC. Installing the DPC involves connecting the supply and test pressure tubing, powering up the unit, and configuring the system through the front panel.
  • Page 32: Cautions

    Warning – Make sure that you connect the proper pressure supply to the correct pressure channel. The pressure range for each channel is identified on the front panel of the 7252. This is depicted using the letter A and B for the two channels and the pressure INSTALLATION...
  • Page 33: Exhaust Port

    15 feet (5 meters) when minimum diameter tubing is used. 3.5.3.1 SINGLE TEST PORT OPERATION - OPTION Some versions of the 7252 allow the instrument to be set-up where the test port of both controllers are connected together. A flag must be set in the [MODE] MENU|Setup|User menu to allow the system to operate in this mode.
  • Page 34: Reference Port

    the lower pressure channel from the higher pressure channel when controlling pressures that are greater than the full scale range of the low pressure channel. This option is only available with instruments where both channels have a full scale pressure range that is greater than 10 psi (69 kPa) and less than or equal to 1000 psi (6.9 Mpa).
  • Page 35: Vacuum Transducer Installation

    SEE U S ER 'S M A N U A L TO TU R N O N . FIGURE 3-1 MODEL 7252 BACK PANEL 3.5.5 VACUUM TRANSDUCER INSTALLATION On permanent absolute models of the DPC’s (15–50 psia), a vacuum sensor is required to zero the instrument.
  • Page 36: Vacuum Sensor Option

    10. Replace the DPC’s cover, plug the power cord back into the DPC, and turn the power on. 3.5.6 VACUUM SENSOR OPTION The DPC is also available with a vacuum sensor option. On a permanent absolute instrument, this sensor is used to zero the Ruska quartz sensor at a high vacuum. On a DPC that has the Evacuated Reference Option, this vacuum sensor is used to monitor the vacuum level in the reference port when the reference port is pulled to a hard vacuum allowing the DPC to operate in the absolute mode.
  • Page 37: Figure 4-1 Model 7252 Front Panel

    A: 1000 psi B: 10 psi FIGURE 4-1 MODEL 7252 FRONT PANEL Numeric Keypad: This includes the number keys, the decimal point [.], and the change sign key [-]. The [UNITS] key changes between units of measure, [MODE] held down for 5 seconds changes the language.
  • Page 38: Figure 4-2 Menu Tree

    Enter Menu State Menu Enter Setup Menu Setup Set high, low & slew limits, control mode, control band and Limits access code Set step size, head correction, filter and display digits User Define user-defined units of measure Units Set baud, parity, data bits, stop bits, GPIB address Remote Set date and time, reset machine, view software version System...
  • Page 39: Tutorial

    The [F3] key places the unit in Vent mode. This opens the test port to atmosphere and rapidly reduces the pressure, [ENTER] is required to confirm the operation. The [F5] key places the unit either the stop or the jog mode and the rotary knob is then used to set the control set-point by the correct step or jog amount.
  • Page 40 CHANNEL A: MAIN MENU This is the channel A Main Menu. The double sized numbers in the top center of the display shows the current measured pressure (0.00 psi diff). The upper left corner shows the current mode of the DPC (MEASURE, CONTROL or VENT). The right side of the screen shows a bar graph displaying the current pressure relative to a user-configurable full-scale value.
  • Page 41 Step 3. When the unit desired is highlighted, press the [ENTER] key on the far right side of the front panel, under the numeric keypad. The display will return to the MAIN screen with the current units. The second part of this tutorial uses the DPC to generate pressure. The pressure supply must be connected and the test port must be connected to a closed volume, in accordance with Section 3.5 of this manual.
  • Page 42: Selecting Language

    4.1.1 SELECTING LANGUAGE The 7252 DPC can operate in a variety of different languages. To select a different language, press and hold the [MODE] key for 5 seconds. The current language will be highlighted. Use the rotary knob to highlight a new language and hit the [ENTER] key to select that language.
  • Page 43: Main Menu

    Absolute). The Main Menu can always be reached by repeatedly pressing [PREVIOUS]. The model 7252 is designed such that all of the commonly used functions are accessible by a direct key on the key pad or from a top level function key. Less commonly used set- up type functions are accessible through the menu function key.
  • Page 44: Setting The Pressure Setpoint

    This function is not available on permanent absolute versions of the 7252. STEP/JOG This feature is only available when operating in the single channel mode. In addition to entering the pressure set-point through the key-pad, the pressure set-point can be changed using either the step or the jog functions.
  • Page 45: Stepping

    pressure step is user defined. The Jog function is most often used when calibrating mechanical gauges such as a dial gauge and the operator wishes to change the pressure until the mechanical gauge indicates a cardinal point. The operator can then read the higher resolution DPC to determine the actual pressure value when the mechanical gauge is indicating a cardinal point.
  • Page 46: Menu | Setup

    Setup is used to configure the system. It includes setting all of the limits, user parameters, user-defined units of measure, remote interface and system setup. On the 7252, the User and Limits screens are separate for each channel and must be set up independently.
  • Page 47: Low Limit

    4.6.1.1.4 Control Band – There are two common pressure control approaches that are available with the Ruska 7252 DPC. One of the most common control styles is an Active controller where the controller remains operative and holds the pressure at a commanded set-point.
  • Page 48: Control

    any added uncertainty in the measurement system due to the controller since the controller is Passive during the high accuracy pressure measurements. As an example, if a 100 psi (690 kPa) full scale DPC was set-up with the Control Off Band at 0.001 psi (0.007 kPa) and the Control On Band set to 0.005 psi (0.035 kPa).
  • Page 49: Step Size

    CHANNEL A: Menu | Setup | User - Menu 4.6.1.2.1 Step Size - In addition to entering the pressure set-point by the key-pad, the pressure set-point can be changed using the step function. The step function is used primarily when the operator is taking pressure steps in equal pressure increments. The size of the pressure step is user defined.
  • Page 50: Atmosphere

    6. Press Position [F4] to select if the position of the Device Under Test is either “Above” or “Below” the 7252. The selected units will be highlighted and appear in the Gas Head description. 7. Use the rotary knob to highlight the label “Gas Head.”...
  • Page 51 thus the conversion factor simplifies to mTorr = kPa x 7500.6180 CHANNEL A: MENU | SETUP | UNITS - MENU 1. The pressure units are defined from the Units | Define | Menu. From the Main Menu (press [PREVIOUS] until the Main Menu appears) press Menu [F6], then Setup [F2], then Units [F3].
  • Page 52: Menu | Setup - Remote

    The options are Standard Communication for Programmable Instruments (SCPI) which is the only interface available for the 7252. 4.6.1.4.3 Serial Interface Set-Up – The operator can set-up the Baud Rate, Data Bits, Parity, and Stop Bits for the Serial Interface.
  • Page 53: Date/Time

    It does not require any external computer or software in order to perform a successful calibration. It also has the capability of being calibrated remotely through either the RS232 or IEEE-488 interface. The 7252 will guide the operator through a menu driven calibration procedure identifying the pressures that should be supplied by a standard.
  • Page 54: Zeroing

    Calibrate [F3]. 2. Press the Access [F4] key. If there is a password in the system other than 0, then you must enter the current valid password into the 7252 before it will allow you to modify the password. 3. Use the numeric keypad to enter the new calibration password.
  • Page 55: Preparing To Program

    The DPC can store up to 1,000 program steps that may be divided among a maximum of 20 named programs. The Program menu operates only on the current channel. The other channel will be in measure mode while the program is running. 4.6.3.1 Preparing to Program Before entering a test sequence, consider the items discussed below.
  • Page 56: Entering A New Program

    programmed individually since the starting set-point is 30 psi and the ending set-point is 20 psi. Detailed instructions for entering these items are given in the sections that follow. 4.6.3.2 Entering a New Program To program the DPC, use the keys on the front panel to change values on the DPC’s program editing screen.
  • Page 57: Automatically Generating A Program

    5. Using the numeric keypad, enter the values for Pressure, Tolerance, Dwell time, and Max time, pressing [ENTER] after each value. The rotary knob may be used to skip fields. 6. At the 0 step, enter the next pressure and the DPC will automatically insert a new pressure step.
  • Page 58: Changing The Name Of A Program

    CHANNEL A: MENU | PROGRAM | EDIT | AUTO - MENU 6. Using the numeric keypad, enter the values for Start, Stop, Tolerance, Dwell time, Max time, number of pressure Points up, and number of pressure Points down, pressing [ENTER] after each value. The rotary knob may be used to skip fields.
  • Page 59: Changing An Existing Program

    CHANNEL A: MENU | PROGRAM | EDIT | NAME – MENU 5. Use the < [F4] and > [F5] keys to highlight a character. 6. Turn the rotary knob to select the character from the character set. 7. To correct a mistake, press Clear [F4] and return to step 5. 8.
  • Page 60: Changing The Configuration Stored With A Program

    show up in the scratch pad located at the bottom of the window. Press [Enter] to accept the edited value. 5. To add a step to the program, first move to the step after the new step. For example, to insert a step between steps 3 and 4, move to step 4. Press Insert [F4].
  • Page 61: Menu | Test

    4.6.4 MENU | TEST The Menu | Test section of the system is used to perform a number of the diagnostic and tuning functions that are available with the 7252. The Sweep and Control test operate on the current selected channel.
  • Page 62: Menu | Test - Sweep Test

    CHANNEL A: MENU | TEST - MENU 4.6.4.1 Menu | Test – Sweep Test The sweep function can be used to automatically exercise the elastic sensing element of the device under test prior to performing a calibration. For the DPC to perform the sweep test, input the high and low set-point pressures, the pressure control tolerance, the dwell time at set-point, and the number of cycles to perform.
  • Page 63: Menu | Test - Self Test

    6. To stop the program, press Stop [F5]. The program will stop running but the DPC will continue controlling to the current set-point. 4.6.4.2 Menu | Test – Self Test The DPC can perform electrical and pneumatic self test to assist in trouble shooting potential problems.
  • Page 64: Menu | Test - Control

    CHANNEL A: MENU | TEST | SHOP1 – MENU 4.6.4.5 Menu | Test – Control The Menu | Test | Control menu of the system is used to tune the controller. On new instruments, the controller is tuned at the factory and therefore, the user should not need to access or make any adjustments to the controller using this menu.
  • Page 65: Menu | Display - Blank

    CHANNEL A: MENU | DISPLAY – MENU 4.6.5.1 Menu | Display - Blank This is used as a screen saver in the 7252. 4-29 LOCAL OPERATION...
  • Page 66 THIS PAGE INTENTIONLLY LEFT BLANK LOCAL OPERATION 4-30...
  • Page 67: Section 5.0: Remote Operation

    SECTION 5.0 REMOTE OPERATION CAPABILITIES The DPC can be operated remotely by a computer. Two interfaces are supported: IEEE- 488 and RS-232. Both interfaces support SCPI (Standard Commands for Programmable Instruments). The IEEE-488 interface additionally supports emulation of a Ruska Single Channel Interface Panel (Models 6005-701 and 6005-761).
  • Page 68: Ieee-488

    The RS-232 connection is a DB-9P connector found on the back panel of the DPC. It is located on the processor board. The following pins are used; all other pins are reserved. Pin # Direction Signal Receive Data Transmit Data ——...
  • Page 69: Device Messages

    4. Repeat steps 2 and 3 to set all parameters needed. DEVICE MESSAGES 5.4.1 SCPI COMMAND FORMAT SCPI mnemonics have two forms: long and short. The short form is all in capital letters. The long form is the entire mnemonic. Commands may use either the short form or the entire long form.
  • Page 70: Ansi/Ieee 488.2-1987 Command Summary

    5.4.3 ANSI/IEEE 488.2-1987 COMMAND SUMMARY *CLS Clear Status *ESE? Event Status Enable Query *ESE <number> Event Status Enable *ESR? Event Status Register *IDN? Identification *OPC? Operation Complete Query (Returns 1) *OPC Operation Complete *RST Reset *SRE? Service Request Enable Query *SRE <number>...
  • Page 71 :TARE :VALUE <number> get/set tare value :STATe ON|OFF set tare state using current press. :LIMit :LOWer <number> low pressure limit :SLEW <number> slew rate limit :UPPer <number> high pressure limit :VENT <number> auto-vent limit CALibration :MODE? calibration edit enabled? :MODE <number> request calibration edit [:PRESsure]? A Pressure...
  • Page 72 Same as PRESsure2 above :VACuum? A Vacuum Same as PRESsure2 above :VACuum11? B Vacuum Same as PRESsure2 above :TEMPerature? A Gas Temperature Same as PRESsure2 above :TEMPerature2? A Sensor Temperature Same as PRESsure2 above :TEMPerature11? B Gas Temperature Same as PRESsure2 above :TEMPerature12? B Sensor Temperature Same as PRESsure2 above...
  • Page 73 :LOWer? returns low cal point :REFerence [:HEIGht] <number> gas head height :MEDium N2|AIR gas head medium :PRESSure11 [:RESolution] <number> sets pressure display resolution :AUTO ONCE returns to default resolution :MODE ABSolute|DIFFerential|GAUGE|TARE :RANGE [:UPPer]? full scale value in units (calibrated) :LOWer? returns low cal point :REFerence [:HEIGht] <number>...
  • Page 74: Example Scpi Commands

    [:EVENT]? read/clear operation event register :CONDition? read operation condition register :ENABle <number> set operation enable mask :QUEStionable [:EVENT]? read/clear questionable event register :CONDition? read questionable condition register :ENABle set questionable enable mask :PRESet clear enable masks SYSTem :BEEPer <freq>,<length> <Freq> ignored :DATE <year>,<month>,<day>...
  • Page 75: Scpi Status Registers

    :meas? MEAS? To set the control pressure setpoint to 50, all of the following commands are equivalent: SOURCE:PRESSURE:LEVEL:IMMEDIATE:AMPLITUDE 50 SOUR:PRES:LEV:IMM:AMPL 50.0 PRESSURE +50 PRES 50 To zero the unit via the remote interface use the following sequence: CAL:ZERO:INIT Enter Zero Mode CAL:ZERO:INIT? Read Status (Mode, Pressure, Temperature, Reference) and Wait Until Stable.
  • Page 76 Bit 5 EBS - Event status bit. Set when an event enabled in ESE occurs. Bit 4 MAV - Message available. Set when a response is ready to be sent. Bit 3 Questionable status summary. Set when an event enabled in QUES:ENABLE occurs. Bit 2 Error/event queue not empty.
  • Page 77: Serial Operation

    SERIAL OPERATION The RS-232 port accepts the same SCPI commands as the IEEE-488 port. commands can be terminated by a carriage return (hexadecimal 0D) or a line feed (hexadecimal 0A). The responses are always terminated by a carriage return followed by a line feed.
  • Page 78 { printf ("GPIB Driver not installed.\n"); return; /*-----------------------------------------------------------*/ /* Initialize 7250 Interface UNIT %FS Set units to percent of full scale */ PRES 20.0 Set control setpoint to 20 %FS PRES:TOL 0.001 Set control tolerance to 0.001 %FS */ OUTP:MODE CONTROL Enter control mode /*-----------------------------------------------------------*/ write_7000 ("UNIT %FS;:PRES 20.0;TOL 0.001;:OUTP:MODE CONTROL\n");...
  • Page 79: Sequence

    unsigned char status7; int retval; /*---------------------------------*/ /* Check for GPIB Interface Errors */ /*---------------------------------*/ if (ibsta & ERR) { printf ("GPIB Status=%4X Error=%d\n"); return 1; /*-----------------------*/ /* Check for 7250 Errors */ /*-----------------------*/ retval = 0; while (!kbhit ( )) { ibrsp (device, &status7);...
  • Page 80 double pressure; /* Pressure read from unit */ status; /* Status register from unit */ check_errors (void); zero (void); void write_7000 (char *s); void request_7000 (char *s); /*--------------------------------------------------------------------*/ void main (void) char *p; /*---------------------------*/ /* Initialize GPIB Interface */ /*---------------------------*/ device = ibdev (0, /* First GPIB Board */ /* GPIB Address of 7250 */...
  • Page 81 /*-------------------------------------------------*/ /* Wait for calibration values to be within limits */ CAL:ZERO:INIT? /*-------------------------------------------------*/ { if (kbhit ( )) { getch ( ); break; request_7000 ("CAL:ZERO:INIT?\n"); sscanf (buffer, "%d,%d,%d,%d", &cstat, &pstat, &tstat, &rstat); if (check_errors ( )) return 0; gotoxy (20, 5); if (pstat == 0) cprintf ("Stable ");...
  • Page 82 /*--------------------------------------------------------------------*/ /* check_errors : display all GPIB and 7250 error messages return TRUE if any errors were found /*--------------------------------------------------------------------*/ int check_errors (void) unsigned char status7; int retval; /*---------------------------------*/ /* Check for GPIB Interface Errors */ /*---------------------------------*/ if (ibsta & ERR) { cprintf ("GPIB Status=%4X Error=%d\r\n", ibsta, iberr);...
  • Page 83 #include <stdio.h> #include <stdlib.h> #include <conio.h> #include <dos.h> #include <time.h> #define TRUE 1 #define FALSE 0 #define TIMEOUT (CLK_TCK * 5) /* 5 second timeout */ #define XON 0x11 #define XOFF 0x13 #define CLEAR 0x03 #define DLE 0x10 #define QUEUE_SIZE 1024 char buffer[QUEUE_SIZE];...
  • Page 84 { serial_close ( ); return; /*-------------------------------------------------*/ /* Read pressure status until setpoint is reached. */ MEAS? Read pressure STAT:OPER:COND? Read status setpoint /*-------------------------------------------------*/ while (!kbhit ( )) { if (!request_7000_serial ("MEAS?;:STAT:OPER:COND?\n")) { printf ("Timeout\n"); continue; pressure = strtod (buffer, &p); status = atoi (++p);...
  • Page 85 if ((status7 & 4) == 0) /* Check error bit */ break; retval = 1; request_7000_serial ("SYST:ERR?\n"); /* Get error message printf (buffer); return retval; /*--------------------------------------------------------------------*/ /* serial_int : receive interrupt for serial port /*--------------------------------------------------------------------*/ void interrupt serial_int ( ) char ch;...
  • Page 86 /* serial_close : turn off serial receive interrupt /*--------------------------------------------------------------------*/ void serial_close ( ) unsigned v; outportb (portbase + 1, 0); outportb (portbase + 4, 0); v = inportb (0x21); v |= 1 << intnum; outportb (0x21, v); setvect (intnum + 8, old_vector); /*--------------------------------------------------------------------*/ /* serial_write : write a single character to serial port /*--------------------------------------------------------------------*/...
  • Page 87: Sample Program 4 - Qbasic Example For 7252

    ch = inqueue[inq_out++]; /* Put character in buffer */ if (inq_out == QUEUE_SIZE) inq_out = 0; if (ch == 0x0A) /* Line Feed? - End of response */ { buffer[i] = 0; return TRUE; else buffer[i++] = ch; buffer[QUEUE_SIZE - 1] = 0; /* Buffer full */ return FALSE;...
  • Page 88 THIS PAGE INTENTIONALLY LEFT BLANK REMOTE OPERATION 5-22...
  • Page 89: Section 6.0: Maintenance

    SECTION 6.0 MAINTENANCE INTRODUCTION Very little maintenance is required for the DPC. This section of the manual discusses suggested maintenance procedures. OBSERVING THE SOFTWARE VERSION NUMBER Follow the steps below to observe the DPC’s software version number. 1. If necessary, press [PREVIOUS] several times to return the display to the Main Menu.
  • Page 90: Removing The Dpc's Cover

    TABLE 6-1 ELECTRONICS SELF TEST Test Action on failure RIC Part # Description Processor Tests the processor chip Replace processor board. 7215-586-3 Clock Tests the real time clock Replace processor board. 7215-586-3 Timer Tests the 10 ms interval timer Replace processor board. 7215-586-3 EEPROM Tests the nonvolatile memory...
  • Page 91: Processor Battery

    open solenoid valves that are powered through the vacuum pump power switch. When the vacuum pump is turned on, the solenoid valve is energized and closes allowing the pump to operate normally. When the pump is turned off, power is removed from the solenoid and the vacuum is vented to atmosphere.
  • Page 92: Preparation

    The sensors coefficients are then shown below the sensor label. On the 7252, there are two primary sensors. The first sensor that is shown is the primary measuring sensor A. This is indicated by the word A Primary displayed in the top of the display.
  • Page 93 7252. The number of pressure points required to calibrate the DPC will vary based on whether the DPC is a 7252 or 7252i and if it has a vacuum (negative gauge) option. The screen will display a table noting the following information;...
  • Page 94: Storing The Coefficients

    2.3 Using your calibration standard, generate the pressure shown in the Apply column. When the measured pressure stabilizes, use the DPC’s numeric keypad to enter the actual pressure applied by the calibration standard and then press ENTER. Do not enter the measured pressure reported by the DPC. If necessary, use the [CLEAR] key to correct a mistake in the edit field.
  • Page 95: Vacuum (Negative Gauge) Calibrations

    6.4.2 VACUUM (NEGATIVE GAUGE) CALIBRATIONS Vacuum mode is an available option. The following configuration should be used when calibrating in the Vacuum mode. FIGURE 6-4 VACUUM (Negative Gauge) CALIBRATION To calibrate in Vacuum mode with the configuration shown in Figure 6-4, the following actions should be taken.
  • Page 96: Vacuum Sensor Calibration - Optional Case Reference Sensor

    2. Connect a pressure standard to the Reference Port of the DPC. Note, on the 7252, there are two reference ports. Typically the RPT is connected to the top reference port. However, this can vary based on the configuration of the 7252. If the barometric sensor does not react when changing the pressure in the top reference port, try the lower reference port.
  • Page 97: Editing The Calibration Coefficients

    Note, on the 7252 each sensor will have its own independent vacuum sensor. 3. If desired, change the DPC’s units of measure (see Section 4) to match those of the calibration standard.
  • Page 98 CAUTION: Never randomly adjust the calibration coefficients. Only qualified personnel with valid backup data should be allowed to edit the coefficients. If the backup coefficients are questionable, perform the calibration procedure in its entirety. 1. Verify that the DPC is in Measure mode (Section 4.0). 2.
  • Page 99: Zeroing

    6.4.6 ZEROING The zeroing procedure is performed to correct for system zero shift and does not require a full calibration. The most important requirement for performing a valid zeroing procedure is to guarantee that there is not a pressure differential between the sensor’s test port and case reference.
  • Page 100: Absolute Instruments

    6. Press [PREVIOUS] to return to the Main Menu. 6.4.6.2 Absolute Instruments A vacuum pump must be connected to the reference port. A vacuum gauge should be installed for measuring the case reference pressure. This gauge should be installed as close to the sensor as possible. There is an 1/8-inch NPT fitting available for this installation inside the DPC near the sensor.
  • Page 101: Rpt - Simulated Absolute Instruments

    6.4.6.3 RPT - Simulated Absolute Instruments Simulated absolute DPC’s contain two sensors that require periodic zeroing. The primary sensor is zeroed according to the instructions in Section 6.4.5.1 or 6.4.5.2. barometric sensor is zeroed according to the following instructions. 1. Verify that the Reference Port is open to atmosphere. 2.
  • Page 102 Using the T-shaped Photocell Centering Tool (RIC # 7252-111), adjust the photocells by placing the tool in the hole in the back of the sensor and turning the tool slightly. The screen will show a number of horizontal lines.
  • Page 103: Optimizing Control

    same width that you observed it moving from tightening the Allen screw, and now offset it in the opposite direction by this same width. 11. Again, tighten the Allen screw. Now the width of the yellow line should be minimized. 12.
  • Page 104 Auto-tune. There are two options available to the operator. Full – This fully characterizes the control function of the 7252. It automatically adjust the control valve biases and aligns the inner loop high control pressure sensor to the high accuracy quartz sensor.
  • Page 105: Fan Operation

    Auto-Tune should be run to characterize the new hardware. FAN OPERATION The fan in the 7252 can be turned on or off. It is recommended to keep the fan ON since this will extend the life of the power supply.
  • Page 106: System Software Update Procedure

    5. When the upgrade is finished, Update7 running on the PC and the 7XXX should both display Complete. 6.8.1 Model 7252 Controller Software Upgrade In addition to the main code, the 7252 include code for the pressure controller. The controller software version can be viewed by pressing the MENU/TEST/REMOTE/SERIAL2 MAINTENANCE...
  • Page 107: Replacement Parts

    Note, when updating the controller code, the 7252 will display various error messages. This is expected. The front display will freeze on the 7252 when the controller code is being downloaded. It will operate properly once the download is complete. Finally, the main software only reads the software versions on power-up.
  • Page 108 Part Number Description 7252-109 7252xi isolation manifold valve body 88-1055 7252xi isolation manifold valve coil 11-763 TFT Display 11-764 Display Inverter Electronic Board 7000-70 Sensor LED Lamp Assembly 7000-71 Sensor Photocell 7252-111 Photocell Adjustment Tool 62-293 Power Supply 23-906 7252-100-005...
  • Page 109: Section 7.0: Preparation For Storage & Shipment

    SECTION 7.0 PREPARATION FOR STORAGE & SHIPMENT NOTE: The procedures given in sections 7.1 through 7.3 must be strictly adhered to in order to prevent damage to the instrument. Failure to follow these procedures will likely result in damage to the DPC during shipment. This damage is not covered by the carrier’s insurance.
  • Page 110 The DPC must be prepared for shipment in the following manner: 1. Ruska Instrument has an RMA procedure in place. Please contact the Customer Service Center to obtain an RMA number prior to returning any equipment to Ruska. Have the following information available when contacting Ruska: a.
  • Page 111: Shipping Instructions

    FIGURE 7-1 PACKING THE DPC SHIPPING INSTRUCTIONS Ruska recommends using air freight for transportation. Surface transportation subjects the shipment to more frequent handling and much more intense shock. In most cases, if surface transportation is the mode of transport employed, handling damage is likely. Again, it is essential that the procedures mentioned in sections 7.1 through 7.3 be strictly adhered to in order to prevent any shipping and handling damage to the instrument.
  • Page 112 NOTES STORAGE & SHIPMENT...
  • Page 113: Appendix Asummary Of Specifications

    APPENDIX A SUMMARY OF SPECIFICATIONS UNCERTAINTY ANALYSIS To perform an Uncertainty Analysis on a measurement device, you must be able to identify all of the parameters that influence the measurement. You must be able to quantify the magnitude of the potential error source and combine these into an overall uncertainty statement.
  • Page 114 could drift to its maximum stability limit at any time and therefore, reducing the calibration interval would not improve the expanded uncertainty of the device. Uncertainty of the Standard used to calibrate the transfer standard. This is the expanded uncertainty of the calibration standard that was used by the manufacturer to calibrate the digital transfer standard.
  • Page 115 it would be doubled to express it at the 2 sigma level (i.e. it would be an 0.01% FS device at a 2 sigma or 95% confidence level.) The following two tables are uncertainty analysis examples for a 7252i based on a three month and a yearly calibration.
  • Page 116 The following two tables are uncertainty analysis examples for a single range 7252 based on a three month and a yearly calibration. Uncertainty Analysis – 3 Month Calibration Interval Uncertainty Ruska Model 7252 (2 sigma) A. Performance – (Linearity, Hysteresis, Repeatability 0.003% of Full Scale...
  • Page 117: Specifications

    Evacuated Reference – Option The two sigma expanded uncertainty of the vacuum sensor used to monitor the reference pressure is estimated to be less than or equal to 10 mtorr (1.33 Pa) per year. This uncertainty component should be combined RSS with the primary sensor uncertainty when operating in the absolute mode with a evacuated reference vacuum sensor.
  • Page 118: Performance Specifications

    PERFORMANCE TABLE A-1 PERFORMANCE SPECIFICATIONS: 7252 Pressure Range 5–1000 psi 1000–2500 psi 15–50 psi 3000 psi (0.34–68.9 bar) (68.9–172 bar) (1–3.45 bar) (210 bar) Mode Gauge Gauge Absolute Gauge Precision 0.003% FS 0.003% FS 0.003% FS 0.01% FS Stability Over 3 Months: 0.0019% RDG/ 3 months...
  • Page 119 GAS SPECIFICATIONS Pressure Source Medium: Clean Dry Air or Nitrogen* ≤50 microns Pressure Source Particle Size Contamination: Pressure Source Max. Moisture Content: -50 °C dew point Pressure Source Max. Hydrocarbon Content: 30 ppm VACUUM REQUIREMENTS Supply Vacuum: 50 liters per minute (minimum) with auto vent feature (absolute units only) Bypass Supply Vacuum Valve for High Pressure Gauge work * Industrial grade nitrogen, 99.5% pure...
  • Page 120 THIS PAGE INTENTIONALLY LEFT BLANK APPENDIX A...
  • Page 121: Appendix Bsummary Of Error Messages

    APPENDIX B SUMMARY OF ERROR MESSAGES Negative error numbers are from the Standard Commands for Programmable Instruments (Version 1991.0). Description and Corrective Action Value No Error. -103 Invalid Separator. Check punctuation in the SCPI command. -104 Data Type. The type of parameter data is incorrect. -109 Missing Parameter.
  • Page 122 (section 7) if necessary. Case Pressure Overrange. Select OK, then reduce the pressure at the case reference port to 30 psia or lower. Mechanical Zeroing Needed. The zero point of the quartz Bourdon sensor is beyond the range of the compensation circuit. The zero is adjusted by the software but should be manually adjusted for complete accuracy.

This manual is also suitable for:

7252i

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