ResultCode (Result Code)

The ResultCode variable holds the results of the communication attempt. ResultCode is set to 0 if communication is successful; it increments by 1 after a communication failure (a failure is an expiration of the timeout period and any Tries). If the Modbus server returns a Modbus exception code, it will be preceded by a minus sign and stored in ResultCode. Error codes returned by the server:

Code	Name
-01	Illegal function: the function code received in the query is not an allowable action for the device. The device may not support the function or it may not be in a state to process the request.
-02	Illegal data address: the data address received in the query is not an allowable address for the device. The combination of the reference number and transfer length may be invalid.
-03	Illegal data value: the value contained in the query data field is not an allowable value for the device.
-04	Server device failure: an unrecoverable error occurred while the device was attempting to perform the requested action.
-05	Acknowledge: the device has accepted the request and is processing it, but a long duration of time will be required to do so. This is a specialized function used in conjunction with programming commands.
-06	Server device busy: the device is engaged in processing a long-duration program command.
-08	Memory parity error: the device attempted to read a record file but detected a parity error in the memory. Used in conjunction with function codes 20 and 21.
-09	Gateway path unavailable: indicates that the gateway was unable to allocate an internal communication path from the input port to the output port for processing the request.
-10	ModbusClient error: received an unexpected function code response from server.
-11	The specified ComPort (or TCP socket) is not opened. There is no connection to the Modbus server.
-16	ModbusClient error: out of comms memory.
-20	ModbusClient error: variable not dimensioned large enough to store results from server.

Type: Variable