SQO Programing

Hi all, I programed the SQO thanks with all the help I got from everyone, but now I need to have all of my outputs to de-energize when the power or the sequencer is stopped, and when the power or sequencer are restarted the outputs that was on when stopped will be on and the sequencer be in the same step it was before stopping. I was wounding if a move statement (MOV) was used to put a (0) in the outputs to de-energize them with a XIO,wounld they come back on when the power or start button is pressed in the same step they was before the XIO was pushed? If that doesn't work, what will?

Answer to Your Prayers

Your probably will need 3 MOV's. First move output pattern to a temporary storage location, Second, move 0 to Outputs, Third, when switch is turned on again, move temporary storage location back to outputs.

Remember, when switch is turned on, SQO will not step to next step until timer finishes current 5-minute cycle. So to return to exact output point, you must save copy of ouptuts, then later recover it when needed.

I made this SQO program several days ago, in anticipation of your current question.

Rungs 5 thru 9 are an SQO that meets all requirements of your problem. Rungs 0 to 4 are merely rungs that load a random pattern into the SQO, using SQL instruciton.

Rungs 8 and 9 are the ones that save the value of current output, and restore it upon restart of the SQO. The RTO timer in RUng 5 is needed to return the SQO to exactly the step it was on when it was stopped.

Thanks Lancie1, for the infor.

The way I would do it, is to take your last example where you send the SQO destination to the bit word, then add an instruction on each rung between the bit and the actual output address with your power off conditions.

This method will be easier for the average technician in the field to understand, and may give you more flexibility later on....

The sequencer will not advance unless it can go from false to true, and will not reset unless it is done (r6:x.pos >= r6:x.len) or you MOVe a value into the control.POSition register, and even then it won't update the destination word until it is scanned as true.
EDIT: Don't use this example verbatim, I WAG'd the addresses and made no provision to reset the RTO...