norman oliver
Lifetime Supporting Member
Hi, I have a program running which is, occasionally, giving me problems. Although I'm a ladder stalwart I've used ST and SFC in its construction due to the nature of the software ( Eurotherm PAC 9 with Eycon HMI & T2750 PLC ).
I have a 20 step SFC auto sequence and also a manual page/screen in which each individual device (e.g. door open/close, ram up/down, pump on/off) can be button operated for set-up or maintenance. Running the sequence requires these devices on the manual page to be off, i.e. Door_open:=0 for instance.
Could these manual instructions interfere with the running sequence, i.e. Door_open:=1 ?
If I had used ladder I would have a n/o contact in a auto/manual rung to isolate manual operation. How, using ST do I negate any instruction on the manual screen?
Your help would be greatly appreciated as I am quite new to using alternatives to ladder.
I have a 20 step SFC auto sequence and also a manual page/screen in which each individual device (e.g. door open/close, ram up/down, pump on/off) can be button operated for set-up or maintenance. Running the sequence requires these devices on the manual page to be off, i.e. Door_open:=0 for instance.
Could these manual instructions interfere with the running sequence, i.e. Door_open:=1 ?
If I had used ladder I would have a n/o contact in a auto/manual rung to isolate manual operation. How, using ST do I negate any instruction on the manual screen?
Your help would be greatly appreciated as I am quite new to using alternatives to ladder.