415U Condor-long-range wireless I/O and gateway
User Manual MN032006EN
Effective May 2018
Modbus error codes
The following are Modbus error response codes that the Master will generate and write to a general purpose analog register (30501,
40501, and so on) in the event of a poll fail.
Dec code
65281
65282
65283
65384
65285
65286
65288
65290
65291
65024
64512
63488
65535
Hex code
FF01
FF02
FF03
FF04
FF05
FF06
FF08
FF0A
FF0B
FE00
FC00
F800
FFFF
Name
Illegal Function
Illegal Data Address
Illegal Data Value
Slave Device Failure
Acknowledge
Slave Device Busy
Memory Parity Error
Gateway Path Unavailable
Gateway Device Failed to Respond
Invalid Responsefrom Slave
Server Offline
Invalid Local Memory Address
No Response to the Poll
Meaning
The function code received in the query is not an allowable action for the server (or slave).
This may be because the function code is only applicable to newer devices, and was not implemented in the unit selected. It might also indicate that the server (or slave) is in the wrong state to process a request of this type.
The data address received in the query is not an allowable address for the server (or slave).
More specifically, the combination of reference number and transfer length is invalid. For a controller with 100 registers, the PDU addresses the first register as 0, and the last one as 99.
If a request is submitted with a starting register address of 96 and a quantity of 4 registers, this request will successfully operate on registers 96, 97, 98, 99. If a request is submitted with a starting register address of 96 and a quantity of 5, this request will fail with Exception Code
0x02 “Illegal Data Address.”
A value contained in the query data field is not an allowable value for server (or slave). This indicates a fault in the structure of the remainder of a complex request. For example, it may indicate that the implied length is incorrect. It does not mean that a data item submitted for storage in a register has a value outside the expectation of the application program.
The Modbus protocol is unaware of the significance of any particular value of any particular register.
An unrecoverable error occurred while the server (or slave) was attempting to perform the requested action.
Specialized use in conjunction with programming commands.
The server (or slave) has accepted the request and is processing it, but significant time will be required to complete this task. This response is returned to prevent a timeout error from occurring in the client (or master).
Specialized use in conjunction with programming commands.
The server (or slave) is engaged in processing a long–duration program command. The client
(or master) should retransmit the message later when the server (or slave) is free.
Specialized use in conjunction with function codes 20 and 21 and reference type 6, to indicate that the extended file area failed to pass a consistency check.
Specialized use in conjunction with gateways. Indicates that the gateway was unable to allocate an internal communication path from the input port to the output port for processing the request. Typically indicates that the gateway is mis-configured or overloaded.
Specialized use in conjunction with gateways. Indicates that no response was obtained from the target device. Typically indicates that the device is not present on the network.
Command type or slave address did not match request (probably another unit).
Could not connect to the Modbus TCP server.
Local address is invalid in the command. The memory location does not exist or is not initialized.
There was no response to the poll message.
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