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4-3
IM XL100C-E
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App
Index
Modbus Protocol
4.3
Modbus Error Response (for Modbus Slave)
When using the Modbus slave function, the XL100 returns the error codes below to the
master device. For the error messages related to communications that the XL100
displays, see chapter 8, “Error Messages.”
Code
Meaning
Cause
1
Bad function code
Unsupported function request. For a list of supported
functions, see section 4.1, “Modbus Protocol Specifications
and Function Codes.”
2
Bad register number
Attempted to read/write to a register that has no
corresponding channel.
3
Bad number of registers
The specified number of registers is zero.
However, no response is returned in the following cases.
• CRC error
• Errors other than those in the above list.