Touch visu status update issue

[p_xatzi]

Control changes state only when status object is changed, but in your case status object value remains the same. If your status object does not represent real object value then don't use it at all.

Hi,

Actually, there are some real cases. Suppose, we have a PLC communicating through Modbus TCP. The main object would energize a power relay (through PLC's output) and from the relay itself we would get the status (through PLC's input). If the relay would not respond for any reason (selector switch, damaged e.t.c.) status would not be sent. This way in visu we would get ON indication instead of OFF state which is normal as long as we did not receive a reply.

However, we could request the state of PLC's after a small delay (we would get value OFF) and then Touch visu would show ON state incorrectly.

P.S. How, is it possible to request the state of some variable through script (as long as LM only updates values on change)? Actually, how to perform a modbus read function which would update LM objects' value?

Thanks!