Control Freak
Member
- Join Date
- Jul 2004
- Posts
- 44
Maybe a dumb question, but this is my first project using the RS5000, so bear with me - I probably missing the obvious.
In my program I'm using the Move instruction in a 'touchscreen' subroutine at the end of my ladder to 'call' up different screens. (by a moving a value to the touchscreens 'call' address)
simply put,
if Fault word 10 is not equal to "0" then call up screen #10
if Fault word 20 is not equal to "0" then call up screen #20
if Fault word 30 is not equal to "0" then call up screen #30
is safety faults is not equal to "0" then call up screen #5
I've done it a hundred times, and it's worked on every PLC I've ever used. In keeping with the 'last rung wins' concept, I arrange the rungs in reverse priority. (Obviously, safety faults take priority over other faults, so they would be the last rung in the subroutine)
When the scan is completed, the last value written to that word would be the value in that word, right?
Here's the dilemma - for some reason, the 'last rung rules' concept isn't working.
If I have faults in multiple words, the 'call up' word changes erratically, and the faults screens flicker like crazy!
If I monitor (trend) the call up word, the value changes all over the place.
I'm sure the reason is simple, but I'm at a loss.
thoughts?
In my program I'm using the Move instruction in a 'touchscreen' subroutine at the end of my ladder to 'call' up different screens. (by a moving a value to the touchscreens 'call' address)
simply put,
if Fault word 10 is not equal to "0" then call up screen #10
if Fault word 20 is not equal to "0" then call up screen #20
if Fault word 30 is not equal to "0" then call up screen #30
is safety faults is not equal to "0" then call up screen #5
I've done it a hundred times, and it's worked on every PLC I've ever used. In keeping with the 'last rung wins' concept, I arrange the rungs in reverse priority. (Obviously, safety faults take priority over other faults, so they would be the last rung in the subroutine)
When the scan is completed, the last value written to that word would be the value in that word, right?
Here's the dilemma - for some reason, the 'last rung rules' concept isn't working.
If I have faults in multiple words, the 'call up' word changes erratically, and the faults screens flicker like crazy!
If I monitor (trend) the call up word, the value changes all over the place.
I'm sure the reason is simple, but I'm at a loss.
thoughts?