panelview 700 real bad problem

i will do the best i can guys. i have a panelview plus 700 talking to a micro logix 1400. using a standard momentary pushbutton with typical bit (b3/15) as a jog button, if some one is holding the jog button and the touch screen is powered down at the same time the device that was being joged continues to run with the screen powered down. Please help!!!

thanks much
jim cav

Possibilities if this will be likely to happen:

1. Don't use the display, use an input tied to an actual switch.

2. Sense the power to the display as a PLC input. Use that to turn off any display controlled outputs.

3. Use a 'max time' timer to clear the bit.

4. Use hitting a protective limit as a signal to clear the bit.

This can happen to any HMI even if you keep it powered up...It can happen because of any communication failure.

Don't use HMI buttons when there are safety implications.

Do monitor the communications if possible and stop any actions that are driven by HMI momentary buttons.

Failing that possibility, put a time limit on things like jog functions...

XIC JOG_PB TON T4:0 1.0 30 0
XIC T4:0/TT OTE DRIVE_JOG

Have a look at S:33/4 "Comms Active" and see if it goes away when you kill the PV+ It may take a couple of seconds to occur, and this may be adjustable on the channel config settings, but changing the timeout for the channel may have other unwanted effects.

What did you expect it to do ?

What I do is configure the Global Connections feature to write the PanelView Plus system clock into a register in the PLC controller. If the value remains the same for more than a couple of seconds I know the PanelView has been disconnected or powered off or put into Configuration mode.

Another mechanism would be to rapidly "ping" the PanelView with a MSG instruction from the MicroLogix; the PanelView's EtherNet/IP driver supports basic CIP functions like the Identity object that you can read with a Generic CIP message. If the MSG doesn't complete in a period of time, you know the PanelView communication has failed.