RSView 32 application monitoring

I've got a bit of a situation I could use some help with. I'm running RSView 32 on a Windows server which communicates with an ethernet I/P control network. The main interface for the application is in the server room which is not routinely manned, and the remote licenses in different parts of the plant are not manned constantly either. Occasionally RSView 32 is stopping, not necessarily crashing, and I need a way to remotely monitor the application to make sure it's still running. RSView generates some critical alarms and when it stops like that it's very possible to have MAJOR issues in the plant.

My first though was to use some sort of tag instruction to set a bit in another PLC on the network which would go false if the program were to stop. I've tried hidden n/c buttons, derived tags, event tasks, and I simply cannot get this thing to give me a simple bit that will go false if the program is not operating. If I periodically clear the target bit then if the application stops the bit will go false and not go back to true.

Have any of you guys tried to accomplish this? Am I totally on the wrong track?

Thanks

Use an event or derived tag in the HMI to create a heartbeat to the PLC(s). In the simplest form, you have a tag in the PLC which is read by the HMI. The HMI uses an event or derived tag to invert the one the PLC is sending, and send it back as another tag. The PLC see's the inversion, and toggles the one it is sending. Use a timer that is reset with a one shot when the HMI sends an inverted value back. If the timer times out, the HMI has failed, or the communications link has.

You can also just use some scripting in the HMI to increment an integer at some interval, say every second, which the PLC reads. If the PLC doesn't see the integer change for more then say two seconds, there is a fault somewhere.

Thanks, yeah that's what I've been attempting to do but it doesn't seem to be working. I'll try to redo it and I'll post a screenshot, maybe I'm setting up the statements wrong.

I set a bit in the target PLC and created a tag in RSView 32 called "ww_comm_bit". I then opened "Derived Tags" and targeted another bit with tag "ww_handshake" in that same PLC. Both tags are set up as digital tags, one referncing a bit in the binary file, and another in a bit in the integer file.

Please see attached screenshots. The derived tag routine is set up in the startup editor and is set to scan every second so it looks like it should be running but it's not setting the bit? If I'm reading the derived tag help correctly simply stating the tag name of the original flag bit should cause the new handshake bit to go true.

What am I missing?

Thanks again

Anyone? I'm really in a bind here and I could use the help...

What parameters do you have set on your Derived Tag Setup screen? If it is set for "Periodic" and a long time period, then it might not update your Derived Tag for many seconds.