Cycle of operation

[boneless]

My 2 cents?

A sequenced controller is a state machine. You will not start again before it has gone through one complete cycle or when it is reset. This cycle is unlikely to be the exact same amount of time every run.

So the cycle will not repeat until it is done and a new start has been provided.

 

[HEAVENKNOWS]

Would I be correct in saying a repeatable operating cycle?

 

[Lancie1]

All cycles are repeatable, but some are more suited to sequencers than others.

What cycle of operation is best suited to a sequencer controller?

The cycle of operation best suited for a sequencer-type controller is one that never needs changes, always runs the same way with no side branches, no differences, no ifs, ands, or buts. It should run staight down the path from Step 1 to Step 2 to the ending step, then repeat or stop.

 

[JRB]

What cycle of operation is best suited to a sequencer controller?

What type of controller is best suited to a sequential cycle of operation?

 

[HEAVENKNOWS]

A sequencer controller?

 

[Lancie1]

What cycle of operation is best suited to a sequencer controller?

The short answer is "a fixed cycle".

I guess that about 90% of the PLC controllers in the world have either a Drum instruction or a Sequence instruction, so have the capability to be programmed as sequence controllers. Even those PLCs that don't have one of those can be programmed with user-defined step relays, a poor-man's substitute for a Sequencer instruction.

Broadly speaking, a sequencer controller doesn't have to be a PLC, but could be a mechanical timed drum controller, or a timed multi-contact relay-type controller such as in a washing machine.

 

[HEAVENKNOWS]

I've said fixed cycle and been marked incorrect ����

 

[Lancie1]

Probably the answer key had some goofy phrase they were looking for, and you didn't word it exactly as they wanted. "Step by step" could be different from a fixed cycle.

There is no guarantee of a fair and just world. Fight for what you believe.

 

[MartB]

I've said fixed cycle and been marked incorrect ����

So what do YOU think the answer is?