wht is osr

[kraj]

hello all
i want toknw wht is exactly a osr bit
how it works

thanking you

 

[ArikBY]

OSR is One Shot Realy
It a bit which go on for one scan time.
From the point it set on until the end of the cycle.

 

[Jeev]

OSR - One Shot Rising. Single pulse triggered from the rising edge.
OSF - One Shot Falling. Single pulse triggered from the falling edge.

 

[Steve Bailey]

http://www.plcs.net/chapters/oneshot18.htm

 

[Mickey]

hello all
i want toknw wht is exactly a osr bit
how it works

thanking you

What processor do you have? There are some differences in the "OSR" instructions
depending on the processor you have.

 

[Ron Beaufort]

from the "overkill" department ...

so how deep do you want to go? ...

the most interesting "one shot" troubleshooting and debugging problems revolve around "power cycles" - such as when the system shuts down - and then subsequently restarts ...

for example, suppose that we use an OSR for a field input switch which was OFF while the system was running ... then while the system is powered down, an operator manually moves a box forward on the conveyor line - which closes the switch ...

Question: when the system is powered back up again, will the OSR "fire" in response to the ON signal from the switch? ...

in other words, do we want our system to "process" the box? ... (label it, count it, fill it, scan it, load it, etc.) ... or just simply "ignore" the box? ...

the correct answer depends on what brand and model processor you're using ...

other questions can come into play when the power goes OFF for more than a few seconds - or whether it just "flickers" for less than a couple of seconds ... also whether you're using AC or DC voltage for the field input signal ...

the best plan of attack is to realize that these considerations for "beyond normal operation" DO INDEED exist - and then experiment with a spare system in order to understand how YOUR particular hardware handles these types of situations ...