{"id":10711,"date":"2020-05-06T11:14:29","date_gmt":"2020-05-06T14:14:29","guid":{"rendered":"http:\/\/kb.elipse.com.br\/en\/?p=10711"},"modified":"2020-05-06T11:14:29","modified_gmt":"2020-05-06T14:14:29","slug":"common-issues-faced-by-modbus-driver-protocol-exception-codes","status":"publish","type":"post","link":"https:\/\/kb.elipse.com.br\/en\/common-issues-faced-by-modbus-driver-protocol-exception-codes\/","title":{"rendered":"Common issues faced by Modbus driver: Protocol exception codes"},"content":{"rendered":"

Question:<\/h3>\n

A common issue faced by Modbus driver<\/a> is this: the communication takes place, but the tag displays an error message. According to the driver log, you can identify a default error message. How can I interpret this message? Which are the protocol exception codes for Modbus driver?<\/p>\n

 <\/p>\n

Solution:<\/h3>\n

Firstly, there are some exception codes expected by Modbus<\/a> protocol; these codes are returned by a device whenever a request is received but can’t be executed, for any reasons. When the driver receives these codes, it will register them in its communication log alongside the \u201cMODBUS exception response\u201d message.<\/p>\n

The following table lists the exception codes as well as their meaning. Codes not listed below are specific to certain devices; therefore, you should look them up in their respective documentation.<\/p>\n

 <\/p>\n

Table:<\/h3>\n\n\n\n\n\n\n\n\n\n\n\n\n
Code<\/strong>
\n(Hexadecimal)<\/strong><\/td>\n		Name<\/strong><\/td>\nMeaning<\/strong><\/td>\n<\/tr>\n
01<\/td>\nILLEGAL FUNCTION<\/td>\n\n

The function code received in the query is not an allowable action for the slave. If a Poll Program Complete command was issued, then this code indicates that no program function preceded it.<\/span><\/p>\n<\/td>\n<\/tr>\n

02<\/td>\nILLEGAL DATA ADDRESS<\/td>\n\n

The data address received in the query is not an allowable address for the slave and therefore cannot be used.<\/span><\/p>\n<\/td>\n<\/tr>\n

03<\/td>\nILLEGAL DATA VALUE<\/td>\n\n

A value contained in the query data field is not an allowable value for the slave.<\/span><\/p>\n<\/td>\n<\/tr>\n

04<\/td>\nSLAVE DEVICE FAILURE<\/td>\n\n

An unrecoverable error occurred while the slave was attempting to perform the request action.<\/span><\/p>\n<\/td>\n<\/tr>\n

05<\/td>\nACKNOWLEDGE<\/td>\n\n

The slave has accepted a request and is processing it, but a long duration of time is required. This response is returned to prevent a timeout error from occurring in the master. The master can then issue a Poll Program Complete message to determine if processing is completed.<\/span><\/p>\n<\/td>\n<\/tr>\n

06<\/td>\nSLAVE DEVICE BUSY<\/td>\n\n

The slave is processing a long-duration program command. The master should retransmit the message later when the slave is free.<\/span><\/p>\n<\/td>\n<\/tr>\n

08<\/td>\nMEMORY PARITY ERROR<\/td>\n\n

The slave attempted to read extended memory, but detected a parity error in the memory. The master can retry the request, but service may be required on the slave device.<\/span><\/p>\n<\/td>\n<\/tr>\n

0A<\/td>\nGATEWAY PATH UNAVAILABLE<\/td>\nUsed alongside gateways. Basically, this code means the gateway couldn’t allocate an internal path to process the request. Therefore, the gateway could probably be misconfigured or overloaded.<\/td>\n<\/tr>\n
0B<\/td>\nGATEWAY TARGET DEVICE FAILED TO RESPOND<\/td>\nUsed alongside gateways. Basically, this code means that no answer was received by the destination device. Therefore, the device could probably be absent from the network.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Related articles:<\/h3>\n
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The articles below all refer to common issues faced by the Modbus driver:<\/p>\n