One valve applying 2 pressures

I have an application where I need to push a (car) shifter button to 2 different forces. I have taken a 5 position, 2 way center port blocked valve and piped it to my cylinder. The input air supplies are piped to a spring return valve. This valve is piped so that if I turn on the other valve, I apply low pressure. If I turn on the spring return valve and the center blocked valve, I apply high pressure. This part is working as I intended, albeit mechanically. The trouble I am having is programming related. No matter what I do, I can not make it alternate every other cycle with high then low (then high, then low) pressure (for 50,000 cycles). I use a load monitoring device to determine the load was met on the button. First pass I want 40 Newtons on the button. I turn on the first valve and I apply the load to the button (the spring valve is not ON at this point). Once 40 Newtons is met, I retract the cylinder. Next I want to apply the high load so I turn on both valves; the spring return switches over to 89N and the center blocked valve applies 89Newtons. then I retract the cylinder. then repeat 40 Newtons / 89 Newtons until the cows come home. I am using an OMRON CPM10 PLC and Syswin 3.4 software. My cylinder has a stroke of about 2" and I am utilizing switches to indicate position (advanced or returned) of the cylinder.

I am looking for a way for the PLC to recoginize 40N met, run 89N. 89N completed, Both 40 and 89 done, repeat. I can't figure out the cycle complete and what to use to repeat the test. I was using Keep/Latch statements to differentiate them, but my unlatch points are causing me problems. Bear in mind that the load monitoring device has two alarms. If I apply 40N, alarm one is on and sends a signal to my PLC. Same thing for 89N but alarm 2 is on, BUT 40N is also on. I think that is why I can't determine how to program the PLC to know the difference.

I read and re-read your post, but I'm still lost...

It might make more sense (at least to ME) if you gave a list of your inputs and outputs, and how these I/O relate to this sequence.

From your description, I'm not even sure if you're using solenoid operated valves, or if the cylinder is actuating the valves, or what???...

Also, how are you measuring the force? Analog input?...

beerchug

-Eric

P.S. Any chance you could post a picture to clear things up?... :nodi:

If I understood your question properly??
Check out this, Its done in Directsoft so youll have to convert it.

Good luck.

Thanks Mike, I guess after re-reading the post there's a lot of information missing. I need to start working on it this morning. I am going to use your post to help me. If I can't get it by lunch, I'll put together a post with pics.

Thanks,
gunner

Too simple?

Would this work?

ALARM_1     ALARM_2    40_NM

--] [---------]/[-------( )--



ALARM_1     ALARM_2    80_NM

--] [---------] [-------( )--