Further educating myself...

[Davek0974]

Well, clearly I have a lot more studying to do

Take the relatively simple sequence in the PDF attached, it operates the cutter.

Requirements are that the clamp is on whenever the cutter is moving, the cutter is a linear slide and can cut both ways, when in auto it can stop at either end. It needs to accept a trigger from other procedures and set a "done" flag to indicate it has finished.

It sounded simple, wrote it down, run it through my head, all seemed ok.

In reality, the clamp only stayed on for the outward stroke and it never registered as having finished.

Hope that makes sense?

Maybe some kind soul could show me the error of my ways, maybe I am not thinking scan-cycle or something???


Many thanks
Dave

 

[osmanmom]

what measurement system you use to determine the length

 

[Davek0974]

what measurement system you use to determine the length

A rule

It does not need one, the jobs are either 75mm, 150mm or 225mm long, no other options. The servo drive accepts step & direction signals from the PLC, I simply used an INT file to hold the various settings and the choice is made by the HMI.

The actual values are meaningless as it is merely the total count of pulses sent, could have worked it mathematically but no point for three values - just use a rule and adjust on the fly until it was correct then store those values in the INT file. The value for 225mm was something like 126,150 so adjusting for accuracy was very easy.

 

[osmanmom]

how to know the PULSE have done the task when sent amount of PULSE

 

[Davek0974]

how to know the PULSE have done the task when sent amount of PULSE

The stepper drive module sends a "Move complete" input back to the PLC. The motor is only moving while pulses are being sent.

 

[osmanmom]

i don't understand your question on post #46

are the problem on V5?

 

[Davek0974]

Yes, V5 must be on whenever V4 is on or off until the carriage on v4 slide reaches either end. i.e. the clamp V5 must be down any time the cutter/v4 is moving.

V4 is a single solenoid 5/2 valve so energise to go out, release to come home but both times the clamp must come down until it is either out or home.

I thought I had this making sense in my simple state control (pdf) but maybe the scan cycle is messing with my logic and I am not seeing it?

 

[osmanmom]

maybe additional sensor need to install when slide reaches?

 

[Davek0974]

It has a sensor at the out position and one at the home position, S7 and S8 on the picture.

 

[dginbuffalo]

I see a few things that confuse me but i just jumped in here at the end:

No finish signal-- cutter state_4 is turned on @ rung 4 and turned off @ rung 5. I don't think it will ever be on at Rung 8.

Next- What triggers start_cut_cycle?

 

[Davek0974]

I have just had a while and moved the cut sequence inside the full-auto sequence, it was previously serving two purposes hence the need for a trigger and done bit.

It will now take its cue directly from the previous state of the auto-run sequence, doing away with line 0000

The done bit is gone now as it simply passes on to the last stage of the auto-run.

I am hoping this will work but I will concentrate on getting the manual cut cycle to work first, that is merely this sequence without a done flag and simply triggered from the manual cut button input, the whole sequence needs to be one-shot.

Getting the sequence to work seems to be the hard bit, I did away with the flip-flop logic and quite a few other lines of code as the state sequence method seemed to me at least to make it unnecessary.

Basically this code now needs to go clamp - cut - unclamp but with the cutter stopping at either end and the clamp coming down regardless of cutter direction.

 

[osmanmom]

few issue,

1.) Sensor for detecting incoming web/foil front on V4.

2.) Sensor for detecing web/foil ending front on V5.

attachment not signal reset for latch b13:1/2/3

 

[dginbuffalo]

Would this work?

 

[Davek0974]

Would this work?

Thanks but not yet.

The cut valve is a single solenoid 5/2 so energise for out stroke, de-energise for home stroke.

To stay at out position, valve must be held on while clamp releases for next feed, then clamp needs to come on while valve is released.

 

[dginbuffalo]

This seems more like what you were looking for??