PLC Help

If the circuit is also known as a 'one-shot', then in ladder logic the output bit goes on for one program scan whenever the input logic conditions are satisfied.

So the one-shot should be used whenever there is a need for an output to be on for one program scan only.

A typical use for this function would be to drive an input to a rotary sequencer, so that whenever the input conditions are true, the sequencer advances by one step only.

Dear Sir,

Thank you very much for giving me such reply. actully this monostable function was used in DOX 1000 (XMP 480 - Messung) PLC. in this PLC there are three types of function , MONOSTABLE, TIMER, & COUNTER. So i was little bit confused what is the meaning of monostable function block, but i hope the information given by you would be useful to me .

once again thank you,

Pinal

I don't want to muddy the issue but I believe that the monostable function is a actually a set/reset also called a latch/unlatch. A transition from false to true of an input of the latch function will make the output bit true and it will stay in that state even if the input bit becomes false. The output bit will stay true until there is a transition from false to true for the input to the reset function.

Regards, Mike

Dear sir,

thank you, i have read about this function from which i have come to know about it, actully just yesterday i have got the book, in which it was stated that the output will remain high for a specific time period which is programmable when there is a satisfied input is given. so the comment no 4 is matching with the answer. once again thankyou for your kind reply.

-Pinal

Good response. The word used to describe different functions varies across the surface of the globe.

This is from a PLC7 manual.

The monostable function block is used to create a pulse of precise duration. This duration is programmable.....

It is either a "one-shot" as mentioned before or a programmed duration (very short time) pulse.

Dear Sir,

Thankyou for your kind reply, i am fully satisfied with your answer

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Good luck

Dear Sir,

thankyou

Pinal