loops

Hi guys! does anyone use twido software for plc? how can i make an enless loop in a program?

I haven't got the software so I can't help you there.

I am curious as to know why you would want to make an endless (that is what you meant when you wrote 'enless' isn't it?) loop in a PLC? It would only cause the PLC to fault, they don't like loops that they can't get out of.

Paul

I do not know what kind of endless loops you are looking for but i used a scan time repeative counter.

here is something I done:



regards
Sherine T

A plc program is an endless loop. Just program

i=i+1

(in whatever way you choose for you plc)in the main program scan and i will increment (and wrap around) for ever. The plc will normally have a specific routine that runs during start up so you can initialise data.

thanks guys! =)
to PLucas: My program is for traffic lights (one plc controls total of 16 lights for an intersection). I have completed the sequence for an intresection and I need it to loop until a certain time.

one sequence runs for a particular schedule block and another sequence for another schedule block (i used real time clock). a sequence must loop for, say, 10 hours and another for 12 hours of a day.

It's for my project in school. I'm interested in PLCs.
PLC units in our school are new and I'm the only one working on a PLC (and the teachers are not much of help). I'd like to suggest this idea in our area. Traffic lights in here sucks!