GE Druck DPI 740 User Manual
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GE Druck DPI 740 User Manual

Precision pressure indicator
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GE
Sensing
Druck DPI 740
Precision Pressure Indicator
User Manual K0200

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Summary of Contents for GE Druck DPI 740

  • Page 1 Sensing Druck DPI 740 Precision Pressure Indicator User Manual K0200...
  • Page 2 © The General Electric Company. All rights reserved...
  • Page 3 DPI 740 User Manual Safety The manufacturer has designed this instrument to be safe  when operated using the procedures detailed in this manual. Do not use this instrument for any other purpose than that stated. This publication contains operating and safety ...
  • Page 4 DPI 740 User Manual Battery Safety This instrument is fitted with three size AA batteries either rechargeable (nickel cadmium) or non-rechargeable (alkaline). Before storing this instrument remove the batteries. When fitting batteries make sure the electrical contacts are clean and observe the correct polarity. The battery compartment should be inspected for corrsion caused by leaking batteries.
  • Page 5 DPI 740 User Manual Abbreviations The following abbreviations are used in this manual. Note: Abbreviations are the same in the singular and plural. acrylonitrile butadiene styrene atmosphere British standard cmHg centimetre of mercury clear to send direct current data circuit terminating equipment data terminal equipment DUCI Druck Universal Communication Interface...
  • Page 6 DPI 740 User Manual Abbreviations continued Ni Cad nickel cadmium outside diameter Pascal printed circuit board parts per million pound per square inch barometric pressure at airfield level (local) calculated sea level pressure including air temperature calculated sea level pressure resonant pressure transducer ready to send RS232...

  • Page 7: Table Of Contents

    DPI 740 User Manual Table of Contents title page Introduction ................1 Specification................2 Accessories and Options.............4 Installation ................5 Battery ..................5 Electrical Connections............6 Initial Settings................10 Operation ..................11 General..................11 Measurement Modes............11 Local (QFE) Measurement...........13 Sea Level (QFF) Measurement ..........14 Altitude Measurement...
  • Page 8 DPI 740 User Manual Table of Contents (contd) title page Communications..............39 Introduction................39 General Command Format..........40 Command Summary............43 Command Set................. 45 Input Commands..............45 Process Commands............. 47 Set-up Commands..............50 Calibration Commands..

  • Page 9: Introduction

    DPI 740 User Manual 1 Introduction The Druck DPI 740 precision pressure indicator uses a silicon resonant pressure transducer producing a pressure reading in units of pressure measurement and altitude. The instrument is contained in a moulded enclosure of a composite ABS material and can be used as a hand-held indicator or, using a retractable stand, as a bench instrument.

  • Page 10: Specification

    DPI 740 User Manual Specification Dimensions Weight: (nominal)..................0.5 kg Size: height = 190 mm width = 90 mm, depth = 36 mm Environmental Temperature: Operating ............ -10 to +50 C Storage ..............-40 to +70 C Pressure medium: ....
  • Page 11 DPI 740 User Manual Specification (contd) Electrical Power Supply Batteries:...............3 x 1.5 V alkaline size AA Connections external power adaptor/charger ............International power jack RS232 serial communications......6-way LEMO type Electrical safety This instrument meets: ........BS EN 61010 as applicable Electromagnetic compatibility This instrument meets: ............

  • Page 12: Accessories And Options

    DPI 740 User Manual Accessories and Options The instrument is delivered with the following: Accessories User manual K200 (this publication). ii. Calibration certificate. iii. Carrying case. Options Enhanced barometric accuracy over the range of 10 to 30 C ..................±0.15 mbar NiCad batteries and power adaptor/charger Adaptor/charger External Power...

  • Page 13: Installation

    DPI 740 User Manual 2 Installation WARNING: DO NOT ATTEMPT TO CHARGE NON-RECHARGEABLE BATTERIES. TO PREVENT ACCIDENTAL CHARGING OF NON- RECHARGEABLE BATTERIES THE CHARGE LINK LK2 MUST BE IN THE DISABLED POSITION  AUTION O NOT LEAVE DISCHARGED BATTERIES IN THE INSTRUMENT LD BATTERIES CAN LEAK AND CAUSE CORROSION HEN FITTING THE BATTERIES MAKE SURE THE ELECTRICAL CONTACTS ARE CLEAN AND OBSERVE THE CORRECT POLARITY...

  • Page 14: Electrical Connections

    DPI 740 User Manual captive screw Figure 2-1 Fitting the Battery 2.2 Electrical connections (Figure 2-2 and 2-3) The optional adaptor/charger is supplied with a set of interchangeable connectors so that the unit can be used worldwide. To change the power pin adaptor push the adaptor from the charger body, align the replacement adaptor and push onto the charger body.
  • Page 15 DPI 740 User Manual RS232 connections Option C is the adaptor cable recommended for use with the RS232 serial communication interface. The adaptor cable has, at one end, 6-pin LEMO type connector and, at the other, a 9- way D type connector. The instrument's serial communication settings and the data terminal equipment (DTE) settings must be the same.

  • Page 16: Electrical Connections

    DPI 740 User Manual Figure 2-2 Electrical connections K0200 Issue No. 1...
  • Page 17 DPI 740 User Manual Figure 2-3 Adaptor/charger connector K0200 Issue No. 1...

  • Page 18: Initial Settings

    DPI 740 User Manual Initial Settings The instrument is shipped with the following settings: Standard Instrument Settings Units of pressure measurement (selected by F2) ........... mbar, inHg, hPa Battery charging link (LK2) ..........disabled Calibration link (LK1) ............disabled ..................

  • Page 19: Operation

    DPI 740 User Manual 3 Operation 3.1 General (Figure 3-1) The instrument is switched on by the ON/OFF push-button and powers up in the last selected mode and units of measurement. The instrument "times-out" after a period of one minute if no push-button selections are made. To keep the instrument in the powered-up state the ON/OFF and MODE push-buttons should be pressed together.

  • Page 20: Measurement Mode Menu

    DPI 740 User Manual Figure 3-2 Measurement mode menu K0200 Issue No. 1...

  • Page 21: Local (Qfe) Measurement

    DPI 740 User Manual Local (QFE) Measurement (Figure 3-3) This is the direct measurement of the absolute pressure sensed at the pressure port. In addition to measuring local pressure the instrument can, with the use of a hose and connection, measure absolute pressure at a system test point. tare measurement mode - units of measurement -...

  • Page 22: Sea Level (Qff) Measurement

    DPI 740 User Manual Sea Level (QFF) Measurement (Figure 3-4) This mode measures the sea level pressure. It is the meteorological presentation (QFF) of barometric pressure at mean sea level and is a calculated value based on the local height above sea level and the local air temperature. Note:QNH is a derivative of QFF without a correction for local air temperature.
  • Page 23 DPI 740 User Manual Entering Local Height and Temperature Data for Sea Level Pressure Measurements The indicator stores the local height and temperature data used in the sea level pressure measurement in nonvolatile memory. To enter this data proceed as follows: Press the MODE push-button to select sea level pressure measurement mode (confirmed by the display showing "Sea"...

  • Page 24: Altitude Measurement

    DPI 740 User Manual Altitude Measurement (Figure 3-5) This mode measures the vertical distance between a level and a specific pressure datum. Measurements of altitude are calculated from local pressure according to ICAO standard atmosphere tables defined in BS 2G 199: 1984. The default pressure datum is the ISA, 1013.25 mbar.
  • Page 25 DPI 740 User Manual Entering a Pressure Datum for Altitude Measurement The indicator stores the pressure datum used in altitude measurement in volatile memory with a default value of 1013.25 mbar. To enter a new pressure datum proceed as follows: Press the MODE push-button to select altitude measurement mode (confirmed by the display showing "ALTITUDE"...

  • Page 26: Processing Measurements

    DPI 740 User Manual Processing Measurements (Figure 3-6) The instrument can process the measurement results in the following ways: Tare  Filter  Max/min  Tare Each measurement can be individually "tared". The tare function substracts the presently measured value from all subsequent measurements.

  • Page 27: Process Sub-Menu

    DPI 740 User Manual Local pressure MODE PROCESS Change units TARE MORE ON - OFF FILTER MORE ON - OFF MAX/MIN MORE value units value units value units value units Figure 3-6 Process sub-menu K0200 Issue No. 1...
  • Page 28 DPI 740 User Manual Entering the Filter Parameters BAND % of FS is the maximum percentage change in reading that can occur before the filter directly BAND = <value>%FS follows the changing pressure. This parameter can be set between 0 and 10% FS.

  • Page 29: Max/Min

    DPI 740 User Manual Switching the Filter ON or OFF To switch the filter on proceed as follows: Make sure the instrument is in measurement mode and displaying pressure. Press F1 to enter the instrument menu. Press F1 to enter view process options. Press F2 to view the next option (FILTER).

  • Page 30: Max/Min Menu

    DPI 740 User Manual FILTER MORE MAX/MIN MORE min value units max value units return to pressure measurement mode Figure 3-7 MAX/MIN menu K0200 Issue No. 1...
  • Page 31 DPI 740 User Manual Viewing the Maximum and Minimum Proceed as follows: Make sure the instrument is in measurement mode and displaying pressure. Press F1 to enter the instrument menu. Press F1 to view process options. Press F2 until the status line shows MAX/MIN. Press F1 to view max/min options.
  • Page 32 DPI 740 User Manual intentionally left blank K0200 Issue No. 1...

  • Page 33: Set-Up Menu

    DPI 740 User Manual 3.3 Set-up Menu (Figure 3-8) To change other less used facilities and background tasks, enter the set-up menu by pressing the SET push-button. Pressing SET again steps to the next sub-menu set. In each sub-menu the function push-buttons F1 and F2 are used to select the required task.

  • Page 34: Battery

    DPI 740 User Manual Battery This sub-menu shows the capacity charge compared to the full charge capacity sub-menu shown as a percentage in 25% bands. UNITS BATTS example: Battery75-100% Units When in the local or sea level measurement modes pressing F2 changes the units of pressure measurement between three preselected units, held in nonvolatile memory.
  • Page 35 DPI 740 User Manual Changing the preselected units of pressure Proceed as follows: Press the SET push-button. Press F2 to select UNITS. Use F1 and F2 move up and down the list of units. Press the SET push-button to select the required unit. Repeat steps 3 and 4 to select the second and third units.

  • Page 36: Time-Out

    DPI 740 User Manual Time-out The time-out period can be set between 1 and 15 minutes (default 1 minute). In the enabled state, if no push-buttons have been pressed, the time-out switches the instrument "off" after the time elapsed. Pressing the ON/OFF push-button "on" resets the time-out and switches the instrument back on.

  • Page 37: Serial Communications

    DPI 740 User Manual Serial Communications (Figure 3-9) The instrument uses RS232 communication parameters as follows: Baud rate - 19200, 9600, 4800, 1200, 600, 300 & 150 Data bits - 7,8 Stop bits - 1,2 Parity - none, even, odd Handshaking-none, software, hardware Notes: The parameters set on shipment are in bold.

  • Page 38: Communications Set-Up

    DPI 740 User Manual Baud Rate = **** Data Bits = * Stop Bits = * Parity HShake Exit set-up, display returns to pressure measurement Figure 3-9 Communications set-up K0200 Issue No. 1...

  • Page 39: Entering A New Pin

    DPI 740 User Manual Entering a new PIN The instrument calibration is protected by a PIN, which must be entered before accessing the calibration menu. The default PIN set at manufacture is 000. Changing the PIN Proceed as follows: Make sure the instrument is in measurement mode and displaying pressure.

  • Page 40: Sending Measurements To A Printer Or Pc

    DPI 740 User Manual Sending Measurements to a Printer or PC The measured pressure or altitude can be sent to a printer or PC through the RS232 communications connector. The instrument sends the current selected measurement mode data. Sending Data Proceed as follows: Set the RS232 communications parameters of the instrument to match the device receiving the data.

  • Page 41: Calibration

    DPI 740 User Manual 4 CALIBRATION The instrument is supplied with a calibration certificate. For the instrument to stay accurate it is recommended that it is checked every 12 months. The recommended equipment for calibration is a  compensated deadweight pressure standard or similar equipment to provide the required accuracy.
  • Page 42 DPI 740 User Manual Procedure (Figure 3-10)  This sub-menu divides into two selections, a one-point calibration and a two-point calibration. AUTION HIS INSTRUMENT CONTAINS STATIC SENSITIVE COMPONENTS HANDLE WITH EXTREME CARE The calibration procedure is protected by a PIN and the CAL option link LK1 located on the PCB.

  • Page 43: Calibration

    DPI 740 User Manual VALID ? Enter PIN CAL. points APPLY PRESS - P1 APPLY PRESS - P1 ENTER APP. PRESS ENTER APP. PRESS <value><units> <value><units> APPLY PRESS - P2 ENTER CAL. DATE repeat procedure above 01/01/96 ENTER CAL. DATE 01/01/96 Exit set-up, display returns to pressure...
  • Page 44 DPI 740 User Manual Two-point calibration Proceed as follows: Make sure the instrument is in measurement mode and displaying pressure. Press SET until the display shows CAL on the status line. Press F1 to select the CAL menu. Use F1, F2 and SET to enter the PIN. Press F2 to select a two point calibration, the display prompts for the first calibration point.

  • Page 45: Maintenance

    DPI 740 User Manual 5 Maintenance 5.1 General User maintenance on this unit is limited to battery replacement, fault finding and cleaning. 5.2 Fault finding Displayed error messages If the pressure sensed by the instrument exceeds 110%  of the full-scale pressure value the display flashes the message OVERRANGE ERROR.
  • Page 46 DPI 740 User Manual K0200 Issue No. 1...

  • Page 47: Communications

    DPI 740 User Manual 6 Communications 6.1 Introduction The instrument can be used either in direct mode or as part of a network, in the addressed mode. The communications protocol used by the instrument is the Druck Universal Communication Interface (DUCI). In this section the commands that apply to the instrument are detailed and described, for further information contact Druck.

  • Page 48: General Command Format

    DPI 740 User Manual 6.2 General Command Format The instrument is controlled by a sequence of letter codes, some commands require numeric values to follow the letters. The correct number of parameters must be sent for the particular command. The instrument accepts upper-case or lower-case letters.
  • Page 49 DPI 740 User Manual The address 99 is a global address recognised by all instruments. As characters are received by the instrument they are instantly echoed on to the next instrument unless the command block character is a `#`. On receiving the termination characters the received destination address is checked for the global address 99 or against the instrument's address.
  • Page 50 DPI 740 User Manual example program #sa?; query instrument address !SA=00; reply address is 00 #fa=1; put instrument in addressed mode #0099ic=p; send command to instrument 00 from instrument 99 input channel is pressure #0099pc=~(ir,10,1); set-up process channel to filter 'input reading ir time constant 10, band 1' #0099iu=0;...

  • Page 51: Command Summary

    DPI 740 User Manual 6.3 Command Summary The following functions can be performed using the serial link: Input Commands IC=<param type> Set-up input Get input reading IU=<index> Set-up input units IA=k Enable automatic sending of input reading Process Commands PC =<process definition> Set-up Process PC =~(IR),<value>,<value>...
  • Page 52 DPI 740 User Manual PIN commands PP=<pin> PIN protect command Automatic Commands AA=<device address> Automatic device address AE=<error mask> Automatic error reporting Read Commands Read battery volts Read instrument type and version number Read error status Protocol Format Commands FC=<flag> Enable/disable message checksum FA=<flag>...

  • Page 53: Command Set

    DPI 740 User Manual 6.4 Command Set All commands are of the format described in 6.2. In the following command description the start and terminating characters have been removed for clarity. Parameters enclosed in [ ] are optional. Input commands Command: - Set-up input Format:...
  • Page 54 DPI 740 User Manual Command:IU - Set-up input units Format: IU=<index> Description: Set-up the units for the input in volatile storage. The units are specified as <index>, defined in Table 6-2. Query: A query of this command returns the index units.

  • Page 55: Process Commands

    DPI 740 User Manual Process commands Command: PC - Set-up process Format: PC = <process definition> Description: This command sets and defines the required process of the instrument. The <process definition> must be in the format shown in the following table: PC =<process definition>...
  • Page 56 DPI 740 User Manual Example: tare PC=T(IR) Full tare of input reading. PC=T(IR,100.00) Define tare of input reading, subtracts 100 from reading. The value specified in the command is in the currently selected units. Note: This tares the value but does not change the displayed value.
  • Page 57 DPI 740 User Manual Command: PR - Get reading Format: Description: Requests the reading. Query: This is a query only command. Example: Reply: OR = 1000.00 reading in mbar Command: PA - Enable automatic sending of reading Format: PA = k Description: Enables automatic sending of input reading.

  • Page 58: Set-Up Commands

    DPI 740 User Manual Set-up commands Command: SA- Set instrument address Format: SA = <nn> Description: Set instrument address to <nn>. Changes the network address of the instrument in the range 0 to 98. Address 99 is used for global commands.

  • Page 59: Calibration Commands

    DPI 740 User Manual Calibration commands C - User Calibration This command allows the user to perform a two point calibration on the output of the device. The calibration routine requires two pressures to be applied within the operating extremes. The software calculates an offset and gain correction to all subsequent readings.
  • Page 60 DPI 740 User Manual Command: CP - Enter Calibration Point Format: CP = <value> Description: The calibration point value is given by <value> in the currently selected units. Query: A query of this parameter CP? returns the number of calibration points already recorded by this command.
  • Page 61 DPI 740 User Manual Command: CN - Get number of calibration points required Format: Description: Returns the minimum and maximum calibration points required to carry out the specified calibration procedure. Example: IU = 0 set-up input as mbar PP = 123 PIN entered put instrument into calibration mode CT = 1 perform two point calibration...
  • Page 62 DPI 740 User Manual Command: CD - Calibration date Format: CD = <dd/mm/yy> Description: Sets calibration date, only valid in calibration mode. Example: CD = 24/01/97 set cal date to 24 January 1997. Query: query date of last calibration. Reply: CD = 24/01/97 Example of a two point calibration IU = 0...

  • Page 63: Automatic Commands

    DPI 740 User Manual Automatic commands Command: AA - Automatic addressing Format: AA = <device address> Description: This command can only be used with the# command header block. It automatically sets the addresses of the instruments in the network to sequentially increasing addresses.

  • Page 64: Read Commands

    DPI 740 User Manual Read commands Command: RB - Read Battery Volts Format: Description: Read battery voltage Example: query battery voltage Reply: RB = <voltage> RB = 3.9 battery 3.9 volts Query: There is a query only command. Command: RI - Read instrument type and version number Format: Description:...
  • Page 65 DPI 740 User Manual Command: RE - Read error status Format: Description: Report errors. This query command reports any error since the last RE? command. The errors are stored as bits (16 bits max) and set if the error occurred. After issuing this command all errors are cleared.

  • Page 66: Protocol Format Commands

    DPI 740 User Manual Protocol format commands Command: FC - Enable/disable message checksum Format: FC=<flag> Description: Format checksum command. Enables/ disables the checksum feature of the data transactions. <flag> = 0 disable checksum feature enable checksum feature Example: FC = 0 disable checksum feature FC = 1 enable checksum feature Query: There is no corresponding query command.

  • Page 67: Key Commands

    DPI 740 User Manual Key commands Command: KM - Local/remote operating mode Format: KM=<flag> Description: Sets the push-button mode so that the instrument can be operated remotely. This command locks/unlocks the push-buttons. Example: KM = L local mode (push-buttons enabled) KM = 2 remote mode (push-buttons disabled) Query:...
  • Page 68 DPI 740 User Manual Table 6-1 Table of Error Definitions The 16-bit hexadecimal mask defined below can be specified using the AE command. It is used for automatic error reporting by the RE message transmitted by the instrument. Bit Error Description syntax error Set if the command syntax was not understood.
  • Page 69 DPI 740 User Manual Table 6-2 Table of Measurement Units The <index> used to identify all the units of measurement are defined below and are used by the IU and SU commands. mbar kgf/cm kgf/m mmHg cmHg 10 - 11 - 12 - 13 - 14 -...
  • Page 70 DPI 740 User Manual Table 6-3 Example Program in QBASIC start: EOFch=26 port%=1 PRINT SPC(20); "DPI 740 Druck Iniversal Communications Interface : Example Program" PRINT SPC (19); "==============================================" PRINT PRINT Before commencing, ensure that the DPI 740 Communications Parameters are set as follows:" PRINT PRINT "Baudrate : 9600, Parity : None, Handshaking : None, Databits : 8, Stopbits : 1"...
  • Page 71 DPI 740 User Manual PRINT #1, "#fa=1"+ CHR$(13); PRINT #2, "#fa=1" + CHR$(13) +CHR$(10); PRINT #1, "#" + address$ + "99"+"ic=p" + CHR$(13); PRINT #2, "#" + address$ + "99"+"ic=p" + CHR$(13)+CHR$(10); PRINT #1, "#" + address$ + "99"+"pc=~(ir,10,1)" + CHR$(13); PRINT #2, "#"...

  • Page 72: Approved Service Agents

    DPI 740 User Manual Approved Service Agents www.gesensing.com K0200 Issue No. 1...

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