S7 300 scan times

Morning

I don't have any experience with Siemens PLCs but I’m being told that a PLC with about 200, I/O, some remote, can process an input and operate a relay output in less than 10ms. Just standard input and output cards
Any thoughts? it’s for electrical protection and I’d usually hard wire and use the PLC for indication but it’s not my design, but I am being asked what I think.



Chris

What do you mean with 'electrical protection'?

Depending on the size of the program, which S7-300 CPU you use, it should be possible. If you just plonk it in the main program.
If you use an interrupt input, it'll be waaaaaaay faster.

Jeebs

By "electrical protection" I mean, to open a set of breakers to prevent danger to persons and equiptment.

basicaly a proection relay operates and opens a local breaker and that is hard-wired, it is also required to isolate four other breakers and the designer has opted to use a S7 300 PLC to distrubute that operation

Chris

If you want to make an applikation with personel-safety, you'll need a FailSafe CPU, in that case I'll think that 10ms will be very ambitious

The designer has now decided to hard wire the protection with the PLC as backup and consequential control.