How to fullfill this task?

HI experts;
System GE 90-30 CPU 352 i used......
I want to enegise a master electromagnetic relay which control the supply of critical output devices. I want if programme excuation takes long time or halt or plc fail then it turns off. and system shutdown. how i full fill this task?
second i see a logic from another person who do the following?
He use IC693APU300 HSC module. Its %Q Address start from %Q0001 to %Q0016. He set the %Q 10,11 and 12 on first scan. These addresses control the three electromagnetic relays.
%Q 10 and 11 reset when over speed occur. And he used %Q 12 to determine PLC Fail. I read the documentation of this module but unable to understand why he used %Q10,11,and 12 why he is not used %Q 1 ,2 and etc.
Please guide me i am stuck here?
Regards

He use terminal 2 and 3 for measure the speed. He configure the Counter type A.

The %Q9, %Q10, %QQ11, and %Q12 bits are used to enable the output points on the high speed counter module. They don't actually turn them on. They just allow the module to turn them on and off based on the preset values you program into the module, either in hardware configuration or by using COMREQ instructions in ladder logic.

Hi;
Yes he reset as i mentioned in the post. But what about the first part of my quesstion
"System GE 90-30 CPU 352 i used......
I want to enegise a master electromagnetic relay which control the supply of critical output devices. I want if programme excuation takes long time or halt or plc fail then it turns off. and system shutdown. how i full fill this task?
"
Regards

What didn't you like about the answers you got in the other thread where you asked that question?

1. When the PLC stops, all of its outputs get turned off. If you have a realy coil energized by a PLC output, the coil will be deenergized when the PLC stops running its program.
2. When the PLC's operating system detects a fatal fault, the program stops running.
3. A 90-30 CPU352 has a fixed watchdog timer of 200 msec. If a single program sweep takes longer than that, the PLC will stop running the program.

OK i agree but i confuse which bit i used to activate the relay in normal condition. like

---| ?? |-------------------------(%Q0001)

which fatal bit i used from the table given in the cpu 352 document.
regards

jcp said:

OK i agree but i confuse which bit i used to activate the relay in normal condition. like

---| ?? |-------------------------(%Q0001)

which fatal bit i used from the table given in the cpu 352 document.
regards

Click to expand...

How about the ALW_ON Instruction.

Stu....

How about %S0007, ALW_ON?

You are asking very basic questions. If I were your boss, I wouldn't let you be working around the PLCs that are controlling the equipment in your facility until you demonstrated a better understanding.

I suggest you connect your PC to your bench PLC and try to find answers using that system before posting here. You will remember the answer you find as a result of your hands-on experimentation a lot better than the answer that's simply handed to you.