Issue
Configuration and understanding 32 bit values.
Environment
Sigma
IC3
Modbus
32 Bit values
Cause
Correct configuration when reading the 32 bit value.
Resolution
Below is a list of the actions carried when attempting to interface an IC3-Modbus to a third party Modbus device. The device instructions were not clear, and therefore this process was worked through.
- The gateway.txt had been configured as had been suggested, but an error messages indicating the function code 4 was not allowed was received.
- Modified the gateway.txt to use function code 3 which corrected the function code error, but now the register address still caused an error.
- Changed the gateway.txt string to 304,3,3,0xC652,1,1,0,0,0 and this eliminated the address errors, but did not return the correct value.
- Changed gateway entry string to 304,3,3,0xC652,1,0x0202,0,0,0 which is 32 bit unsigned value data not swapped. This still returned an incorrect value.
- Changed gateway entry string to 304,3,3,0xC652,1,0x1202,0,0,0 which is 32 bit unsigned value data swapped. This returned the correct value.
For a copy of the Gateway.txt file click HERE.