•Parameters passed with the execute command are not proper. Refer to the Server interface specifications for correct parameter syntax and range.
•The execute command string has some extra space characters. The Server does not accept extra space characters in execute commands. Please follow the Server interface specifications strictly.
•The DDE execute command is not supported for the topic on which it was issued.
Device <device name> DEAD
The device is declared DEAD as a result of communication failure. This means the device has not responded to repeated queries in a certain time and the system assumes that there is some problem at the device keeping it from responding, that the device is dead for the moment. Dead devices are scanned occasionally to see if they have come back
Device <device name> ACTIVE
A previously DEAD device has resumed communications.
<device name> device got deleted – discarding packet
This is an informational message. A client application deleted a topic and the Server is deleting a scheduled communication packet.
Error allocating new topic (<topic>, <toolkit id>) => 0
The Server is unable to initiate a DDE transaction with the topic. The possible causes are :
•The topic is not configured on the Server. Configure the topic in the Server.
•The communication port associated with the topic could not be opened or initialized properly. In this case, the Server displays communication
•The device type of the topic is not configured. Configure the topic’s Generic Device Type in the Server.
Exception Response, Error Code = <exception code> : <exception code string>
A slave device returned an exception code to a request from the Server. Following are the common exceptions:
•Illegal Function — The function code sent by the Server is not supported by the slave device.
•Illegal Data Address — The data address requested by the Server is not supported by the slave device.
•Illegal Data Value — The data value sent by the Server for a Holding register or a Coil is not a proper value for the particular register.
•Slave Device Failure — A slave device has detected an internal failure.
•Failure in Associated Device — An external device connected to the slave device has failed and the data requested cannot be sent. The
DDE Server User’s Guide | Chapter Five - Troubleshooting • 61 |