-
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
32