 | 1 | initial version |
There is a capture attached to 13734: Modbus dissector - FC2 Response reference number which uses FC 3. Have not found an example with FC 4.
(modbus.func_code == 3) && (modbus.regnum16 == 4)
Looks like you need to know if the register is a modbus.regnum16 or modbus.regnum32 field.
Or brute force it:
(modbus.func_code == 3) && ((modbus.regnum16 == 4) or (modbus.regnum32 == 4))
