GE Sensing RPT 301 Digital Output Pressure Transducer User Manual K177
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RPT 301 Digital Output Pressure Transducer User Manual K177 © Druck Limited 1998 This document is the property of Druck Limited and may not, either in part or whole, be copied or otherwise reproduced, communicated in any way to third parties, nor stored in any Data Processing System, without the express written authority of Druck Limited. K177 Issue No.
K177 Issue No.
RPT 301 User Manual i 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. Do not apply values greater than the maximum value stated. This manual contains operating and safety instructions that must be followed for safe operation and to maintain the instrument in a safe condition.
ii RPT 301 User Manual Abbreviations and Symbols The following abbreviations are used in this manual. Note: Abbreviations are the same in the singular and plural.
RPT 301 User Manual iii Table of Contents 1 1.1 1.2 Introduction ................................... 1 Description ................................................ 1 Specification .............................................. 1 2 2.1 2.2 2.3 Installation ..................................... 4 Mounting the Transducer ......................... 4 Pressure Connection ................................ 4 Electrical Connection ................................ 6 3 3.1 3.2 3.3 3.4 3.5 3.6 Operation .........
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RPT 301 User Manual 1 1.1 1 Introduction Description The RPT 301 Digital Output Pressure Transducer measures air pressure applied to the connection port and produces an electrical output. It comprises a resonant sensor connected to a printed circuit board to produce a serial digital output and is contained in a metal enclosure to IP65 standard.
2 RPT 301 User Manual Power supply Electrical Safety: .......................................... EN61010 (IEC 1010) as applicable Voltage .............................................................. 4.5 to 32 V DC Power .......................... 0.6 Watts at 5 V to 0.75 Watts at 32 V Electromagnetic compatibility ............................................................ EN50081-1 (emissions) ............................................................. EN50082-2 (immunity) Switch on Settling Time: .
RPT 301 User Manual 3 Accessories The following items are delivered with the instrument after manufacture. User manual K177 (this publication) Calibration certificate Mating electrical connector (if ordered) K177 Issue No.
4 2 RPT 301 User Manual Installation Installation must be carried out by a qualified technician. 2.1 Mounting the Instrument (Figure 2.1) The instrument can be mounted on a vertical surface using two screws or bolts to a maximum diameter of 4 mm. Figure 2-1 Mounting Arrangement 2.2 Pressure Connection The pressure port is a G1/8. If a pipe is connected to this port a bonded seal must be used.
RPT 301 User Manual 5 Figure 2-2 Instrument Dimensions K177 Issue No.
6 2.3 RPT 301 User Manual Electrical Connection The electrical connector is a 10-way connector (MIL C26482) for serial, parallel and power connections.
RPT 301 User Manual 7 The start-up +ve and -ve connections must be connected for the instrument to operate. There are many ways of connecting the start-up facility for example: Power control The current consumed by the instrument is approximately 1 mA at 3 V, 2 mA at 5 V rising to 16 mA at 32 V. If necessary, when using a supply greater than 5 V, a series resistor can be used to reduce the current drain to 1 mA.
8 RPT 301 User Manual Communications The installed instrument is controlled by the serial data interface. Software or hardware handshaking can be used on the RS232 interface and only software handshaking on the RS485 interface. Changing the communication interface standard (Figure 2-3) The communication interface standard is set at manufacture to RS232 but can be changed as follows: Remove the lid of the instrument to gain access to the PCB.
RPT 301 User Manual 9 LK1 PL3 LK2 B A B B PL1 Figure 2-3 Changing the communication interface K177 Issue No.
10 RPT 301 User Manual Screening Make sure that the chassis connection between the control computer and the instrument is continuous. Use screened cable and bond the cable screening to the connector shell of the instrument and to the computer enclosure. computer screened cable RPT 301 enclosure connect screen to connector shell Screening to ensure EMC performance K177 Issue No.
RPT 301 User Manual 3 3.1 11 Operation System Operation The frequency output from the sensor is counted for a fixed number of cycles. A mid-scale pressure gives a measurement period of approximately 0.5 seconds. During this time a high frequency clock is also being counted and at the end of the measuring cycle it is this value which is transferred to the processor for conversion into its pressure equivalent. Measurement cycles are continuous, unless specifically interrupted (see the G command).
12 RPT 301 User Manual Command Summary Table Command Function Measurement Return stored reading R * Return stored reading G Get New Reading A Auto send reading X Auto send from power-up Set-up U Set units F Set filter B Set reading resolution O Set communication parameters S Status I Identity User calibration C P CR CRLF User calibration (linearity) Change protection PIN Command Terminators * Short form of the 'R' command K177 Issue No.
RPT 301 User Manual 3.3 13 General Command Format The instrument is controlled by a sequence of single letter commands. Some commands require one or more numeric values to follow the letter, the correct number of parameters must be sent with this type of command. All command fields must be separated by a comma. The instrument accepts upper-case or lower-case letters.
14 RPT 301 User Manual 2. U, O; G; R; G; R; U, 16; G; R; G; R; G; R; A, 100 Reply: Reading 1 mbar Reading 2 mbar Reading 3 psi Reading 4 psi Reading 5 psi Then at 100 second intervals - Reading psi This command string sets the instrument units to mbar, returns two consecutive readings, changes units to psi, returns three consecutive readings and then selects auto-send mode with a period of 100 seconds between readings.
RPT 301 User Manual 3.4 15 General Reply Format For commands that have a reply string, the reply terminator
16 RPT 301 User Manual Error Message Format The form of the error message: ERROR nn - where nn is a decimal number Defined error numbers are: 01 - Bad command 02 - Bad password 04 - Bad data detected by checksum 08 - Data out of range 16 - Hardware fault 32 - Pressure outside range 64 - System not ready Error messages are sent when an error is detected.
RPT 301 User Manual 17 3.6 Detailed Command Definitions Measurement Commands R - Return stored reading This command retrieves the current stored reading, as the reading is the stored and filtered (if the filter is selected) there will be no delay in the reply. Command: R Reply: nnnnnnnUNITS Where: ‘nnnnnnn’ is the stored reading as a floating point number ‘Units’ are the units for nnnnnnn (i.e. mbar, mH2O, psi etc.) G - Get reading This command initiates a new measuring cycle.
18 RPT 301 User Manual Command: A,nnnnnn Where: ‘nnnnnn’ is a number between 1 and 999999. This is the period in seconds between successive transmissions. Reply: None Result: A reading is transmitted every nnnnnn seconds. The transmission format is the same as the reply of the ‘R’ command. X - Auto Send from switch-on The ‘A’ command is cancelled by any following commands and is not restored at switch-on.
RPT 301 User Manual 19 Set-up Commands U - Unit Set-up This command sets the units of the pressure measurement; the selection is nonvolatile.
20 RPT 301 User Manual F - Filter Set-up This command sets the instrument reading filter coefficients. Command: F, step, average Where: step is a pressure band within which the filter operates. If the pressure steps outside this band, the filter is bypassed. This gives an unfiltered response to non-noise step changes. step takes a value expressed as a percentage (0 100%) of full-scale. If step = 0 then the filter is disabled. average is the number of sequential readings (1 99) averaged by the filter.
RPT 301 User Manual 21 O - Set Communications Options This command sets the communication port parameters to match those of the control computer. Note: When changing these settings care must be taken to avoid losing communication with the instrument. If this should happen the default communications settings can be restored (those operational at the time of shipment) by moving Link 1 to the ‘A’ (Restore) position and switching the power off and back on.
22 RPT 301 User Manual S - Status This command returns the instrument status. Command: S Reply: STATUS nn Where nn: 01 = Frequency outside limits 02 = Diode voltage outside limits 04 = Electronics failure Combination errors: Result: a status 06 represents diode voltage and electronics failure. no change I - Identity This command requests the unit to send items of data which describe the unit identity.
RPT 301 User Manual 23 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 use of a Class A compensated deadweight pressure standard is recommended. The following procedures should be carried out in a controlled environment by qualified personnel. If the accuracy of the instrument is not within the specification, carry out a calibration adjustment procedure.
24 RPT 301 User Manual The calibration routine requires a minimum of two pressures within the operating extremes (maximum of six pressures). The instrument software calculates an offset and gain correction to be applied to all subsequent readings using a statistical best straight line method. For single point calibration, the gain factor is set to unity. Notes 1 For the pressure sensor to rapidly respond to the applied pressure, disable the filter by sending the filter command F, 0,0.
RPT 301 User Manual 25 P - Change PIN This command changes the PIN (Personal Identification Number) that protects the calibration data. The instrument is shipped with the PIN 000. If the PIN is lost, the default (000) may be restored by fitting the ‘default’ link and switching off and then on. Note: Restoring the defaults restores ALL of the factory settings including the communication parameters.
26 RPT 301 User Manual 5 Maintenance 5.1 General User maintenance on this instrument is limited to checking the LED indicator, a diagnostic mode and cleaning the case. 5.2 LED Indicator With the lid of the instrument removed, an LED located on the PCB flashes when a pressure conversion is carried out. This indicates that the instrument has power, that the processor is functioning and the transducer frequency and diode voltage are within normal limits. 5.
RPT 301 User Manual 27 Mode 2 “K00”,Coeff 1
28 5.5 RPT 301 User Manual Approved Service Agents Find approved agents for the servicing of Druck Instruments at: www.gesensing.com K177 Issue No.
