Monitor I/O server communications status

For each topic name being used, you can use a built-in discrete item, $sys$status, to monitor communication status with the I/O Server program. The $sys$status item is set to 0 when a communication failure occurs. The $sys$status item is set to 1 when communicating normally with the I/O Server program.

Note: When you monitor the status of a topic using the IOStatus item, at least one I/O point must be active for the monitored topic.

From the InTouch HMI, you can read the state of the server communications by defining a tag and associating it with the topic configured for the device by using the word $sys$status as the Item Name. For example, if WindowViewer is communicating with a PLC using the Modbus DAServer, the Access Name definition is similar to the following example:

To monitor the status of all communication to the topic PLC1, create the following tag definition:

In Excel, you can read the status of the PLC communications by entering the following formula in a cell:

=SIMULATE|PLC1!'$SYS$STATUS'