Hello all,

Is it possible in the HMI to detect loss of PLC communication ? And the other way is it possible to detect loss of HMI communication ?

Regards Per Olof

For the PLC u can use a certain watchdog bit.

KTP600 -> Connections (Select your connection) -> Tab "Area pointer" -> Active [v] Coordination. Connect this word to a tag to your PLC. It's a word filled with bits. Use F1 for help on that on which bit is the watchdog bit.

It's probably bit2. I declared like a word "coordinates" then i select coordinates.%X2 for selecting bit 2. 

Write code that alarms when the bit isn't changing and u detected the connection failure.

The HMI itself can also detect it trough  HMI alarms -> System events. You can do something with the system event 140000 and 140001.

I can't remember clearly how to check events in the HMI itself. But hope i helped u with this.

Edit: This last doesn't work on basic panels, use the solution from huggy_d1.

Thanks for the respone! 

But I can not find the correct documentation about the bits for Coordination. Where should I write the code for the panale KTP600 ?

Regards Per Olof

You can check any kind of communication if you send a toggle bit and checking ON and OFF state at receiver. For example: If you send a toggle bit of 1s, you would check if ON-state or OFF-state at receiver exceeds 500 ms. If so, communication is broken. To compensate for any delays due to communication, you could do the check at 550ms.

regards

Hello Per Olof

its hard to program this with a Basic Panel. The reasons are that you cannot use  the Events of System Messages, so you have no trigger witch tells you tha the connection is lost.

Also you cannot do scripting to do a if..then...else if a specific Value is not set by the PLC.

In this little Panels you can only display the System Messages for a longer time or you have to create a circle for example and you let this Circle switch color with a Toggle Tag in your PLC (for example ecery second) so when the connection is established the Color changes. if its broken the color ist static.

Bye Murof