error in CI867 number -4901 and -4902
Do you know what is a error -4901 and -4902 in modbus tcp ci869 in block mbtcpread?
in one slave i have -4901 and other different slave i have -4902
i use the block exception for check and ID appear this error
i used mbtcpread and return this error
i have errors in hardware configuration?
what is loopback? how works ?
Please dind the description in attached screenshots for error "-4901" & "-4902".
-4901 basically states that your function code is not matching.
-4902 states the data range is not matching. If you have wrongly mapped the function code then obviously this error will come.
here are the types & range of modbus registers
Object type Access Address Space Coil Read-write 00001 - 09999 Discrete input Read-only 10001 - 19999 Input register Read-only 30001 - 39999 Holding register Read-write 40001 - 49999
Check the Start address syntax and examples given below,
Read Coil status(FC1)
Read Input Coil status(FC2)
Read Holding Registers status(FC3)
Read Input Registers(FC4)
Force Single Coil(FC5)
Force Multiple Coils(FC15)
Force Single Preset register(FC6)
Force Multiple Registers(FC16)
Example1: Holding Register – 1550 (Decimal) -> %QW10#1550
Example2: Input Register – 1550 (Hexa) -> %IW16#1550