# ModbusErrorCode ## `ModbusErrorCode` (`ENUM`) `TYPE` ModbusErrorCode: (NO\_ERROR) Attributes: `qualified_only` InOut: | Name | Initial | Comment | | ------------------------------------------------ | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | NO\_ERROR | 16#0 | The communication was successful | | EC\_ILLEGAL\_FUNCTION | 16#1 |

Exception-Code-DEVICE: 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 could also indicate that the server (or slave) is in the
wrong state to process a request of this type, for example
because it is unconfigured and is being asked to return
register values.

| | EC\_ILLEGAL\_DATA\_ADDRESS | 16#2 |

Exception-Code-DEVICE: 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.

| | EC\_ILLEGAL\_DATA\_VALUE | 16#3 |

Exception-Code-DEVICE: 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, such as that the implied length is
incorrect.

| | EC\_SLAVE\_DEVICE\_FAILURE | 16#4 |

Exception-Code-DEVICE: An unrecoverable error occurred while
the server (or slave) was attempting to perform the
requested action.

| | EC\_ACKNOWLEDGE | 16#5 |

Exception-Code-DEVICE: The server (or slave) has accepted
the request and is processing it, but a long duration of
time will be required to do so.

| | EC\_SLAVE\_DEVICE\_BUSY | 16#6 |

Exception-Code-DEVICE: 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.

| | EC\_NEGATIVE\_ACKNOWLEDGE | 16#7 |

Exception-Code-DEVICE: Slave cannot perform the programming
functions. Master should request diagnostic or error
information from slave

| | EC\_MEMORY\_PARITY\_ERROR | 16#8 |

Exception-Code-DEVICE: 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.

| | EC\_GATEWAY\_PATH\_UNAVAILABLE | 16#A |

Exception-Code-GATEWAY: 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. Usually means that
the gateway is misconfigured or overloaded.

| | EC\_GATEWAY\_TARGET\_DEVICE\_FAILED\_TO\_RESPOND | 16#B |

Exception-Code-GATEWAY: Specialized use in conjunction with
gateways, indicates that no response was obtained from the
target device. Usually means that the device is not present
on the network.

| | EC\_UNKNOWN\_CODE | 16#C | Exception-Code is bigger than 16#000B and therefore unknown | | REFERENCE\_TO\_MODBUS\_CLIENT\_MISSING | 16#F00 |

Link to the client or to the data of the instance of
ModbusValue is missing (FB ModbusValue and Method
OnResponseComplete)

| | REQUESTED\_DATA\_TO\_LONG | 16#F01 |

The length of the requested data is too long for processing
in a single request (FB ModbusValue)

| | ILLEGAL\_RESPONSE\_DATA\_LENGTH | 16#F02 |

The length of response data does not match the length of the
request data (Method OnResponseComplete)

| | READ\_TIMEOUT | 16#F03 |

There was no response message from the server in the
expected time (FB ModbusClient\_TCP)

| | INVALID\_CRC | 16#F04 | The CRC checksum was not correct (RTU-protocol only) | | COMMUNICATION\_ERROR | 16#F05 |

The TCP-Stream-Receive-Instruction reports an error (not
used in FB ModbusClient\_TCP)

| | INVALID\_RESPONSE\_TID | 16#F06 |

The response header was invalid (Transaction-ID) (Method
ResponseComplete)

| | INVALID\_RESPONSE\_ADR | 16#F07 |

The response header was invalid (Unit-ID) (Method
ResponseComplete)

| | INVALID\_RESPONSE\_FC | 16#F08 |

The response header was invalid (Function Code) (Method
ResponseComplete)

| | SEND\_TIMEOUT | 16#F09 |

The query message couldn’t send without a fault (FB
ModbusClient\_TCP)

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