Sigma - Configuration of an IC3-Modbus working with 32 bit values.

Product_Support · ‎2018-09-10

Issue

Difficulty in configuring and interpreting 32-bit values when interfacing an IC3-Modbus with a third-party Modbus device.

Satchwell BAS & Sigma

Incorrect configuration of the gateway.txt file and unclear device documentation can read to errors in reading 32-bit values.

The following steps outline the troubleshooting and resolution process:

Initial Configuration Attempt
- The gateway.txt file was configured as per initial guidance.
- Error encountered: Function code 4 was not allowed.
Function Code Correction
- Modified gateway.txt to use function code 3, resolving the function code error.
- New issue: Register address still caused an error.
Address Correction Attempt
- Updated string to:
  304,3,3,0xC652,1,1,0,0,0
  This eliminated address errors but did not return the correct value.
Data Format Adjustment (Unswapped)
- Changed string to:
  304,3,3,0xC652,1,0x0202,0,0,0
  This represents a 32-bit unsigned value (not swapped).
  Result: Still incorrect value.
Final Configuration (Swapped)
- Updated string to:
  304,3,3,0xC652,1,0x1202,0,0,0
  This represents a 32-bit unsigned value (swapped).
  Result: Correct value returned.