Hamilton Sundstrand Company Fuel Metering Valves XVG - Manual (Page 32)

- Only one host master can send request message at a time.
- Each XVG/eXVG unit on the same network must have a unique address.
- Adhere to the tables of registers provided and their allowable data range.
- Do not attempt to write to any register if you are not sure of the consequence.
- Do not write to registers that are for options your XVG/eXVG does not have.
Failure to do so can result in erratic control and/or damage to equipment. Care
must also be taken that the process cannot cause damage to property or injury to
personnel if the wrong commands are sent due to operator error or equipment
malfunction.
Handling Communication Errors
- Reading from or writing to a register that does not exist or is currently
disabled will result in a “time-out response”, or in other words, the
XVG/eXVG will not reply with a message.
- Messages with the wrong format, timing, or CRC are ignored.
- Writing to a read-only register, writing with out-of-range data, or writing with
improper permission will result in response error messages.
- It is the user’s responsibility to handle the error appropriately and determine
whether to resend the message or halt the operation.
Following are a few sample procedures for XVG/eXVG Modbus application:
10.1 Real-Time Status & Parameters Upload Procedure
Following are examples of the real time parameters that can be read at anytime.
Register
Number
XVG/eXVG Parameter Name Description Type
7000 IDM_POSININCHES Valve Position in inches Float
7002 IDM_INPUTPRES Input Pressure, PSIA Float
7004 IDM_OUTPUTPRES Output Pressure, PSIA Float
7008 IDM_MEASFLOW Measured Flow, PPH Float
7014 IDM_GASTEMP Gas Temperature, degrees F (includes TEMPOFF) Float
7016 IDM_VOLTS3PT3 3.3V supply voltage, Volts Float
7018 IDM_PRESSRATIO Pressure Ratio Float
7020 IDM_DMDININCHES Position Demand in inches Float
7074 IDM_TEMPAMB Approx. ambient temp. of electronics cavity, deg C Float
7084 IDM_VOLTSPOS15 +15V supply voltage, Volts Float
7086 IDM_VOLTSNEG15 -15V supply voltage, Volts Float
7104 IDM_MOTORCUR Motor current, approximation in Amps Float
7106 IDM_TIT Total inches traveled Float
Table 23: Parameters Upload for Status
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