Autonics TM Series - Exception Response-Error Code

1 Modbus RTU Protocol
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1.8 Exception response-error code
If occurs an error, send a response command and transmit each Exception Code after set(1) the
highest-level bit of received command(Function).
Slave address
Function
+80 H
Exception
code
Error check(CRC16)
Low
High
1Byte 1Byte 1Byte 1Byte 1Byte
 ILLEGAL FUNCTION (Exception Code: 01 H): A command that is not supported
 ILLEGAL DATA ADDRESS (Exception Code: 02 H): Starting address of queried data
is inconsistent with transmittable address from the device.
 ILLRGAL DATA VALUE (Exception Code: 03 H): Numbers of queried data are
inconsistent with the numbers of transmittable (transferable) data from the device.
 SLAVE DEVICE FAILURE (Exception Code: 04 H): Not properly completed the
queried command (order).
Read the output status of non-existing coil 001001(03E8 H) [ON: 1, OFF: 0] on Slave(Address
17) from Master.
 Query (Master)
Slave address Function
Starting address
No. of points
Error check(CRC16)
High
Low
High
Low
Low
High
11 H 01 H 03 H E8 H 00 H 01 H ## H ## H
 Response (Slave)
Slave address
Function
+80 H
Exception Code
Error check(CRC16)
Low
High
11 H 81 H 02 H ## H ## H
CRC16