Time Measurement

HI EXPERTS
I HAVE A PNEUMATIC CYLINDER HAVING TWO REED SWITCHES AND ONE SOLENOID VALVE WHICH CONTROL ADVANCE AND RETURN OF THE CYLINDER .
I WANT TO MEASURE THE TIME TAKEN FOR THE CYLINDER TO EXTEND FROM ITS NEUTRAL POSITION (RETURNED POSITION).
I WONDER WHAT IS THE BEST METHOD TO MEASURE ANY HELP OR IDEA MUCH APPRECIATED .

THANKS EXPERTS.

This is what I would do but I want to see what the pros suggest, wait for their answers please.

Use a retentative timer that is triggered to start when it leaves the return reed switch and stops by the return reed switch NOT instruction.
Cycle once and see what the retained time is.
-|/|-----------------------|TMR|---
Naturally set it for millisecond range to get most accurate reading.

Depending on brand it may take a little more effort to develop a retentative timer.

Ron's method measures the total extended time (or, more accurately, total "not retracted" time). If you just want the "time to extend" you can try this:

 VALVE SOL.   EXT. SW.

----] [---------]/[----------| TMR |

*
Though this will not include any travel past the extended switch, if that switchg turns on near the end of stroke (where I've found a lot of people set them)...

Also realize that the time recorded will be fairly accurate, but not perfect due to I/O response and/or scan time issues. How accurate do you need to be?

beerchug

-Eric

Eric,

When you show "ladder-type" suff, try this...

<size=4><b>

 VALVE SOL.   EXT. SW.

----] [---------]/[----------| TMR |

</b></size>
where the angle brackets "<" and ">" are replaced with square brackets.

Yeah, I know... I've gotten lazy... zzzzz

I used to bump up the font size to 3 (4's a little overkill I think). Bold's not a bad idea though...

I had suggested to Phil a while back that maybe he could add that to the script for the <LADDER> code (see the blue text in THIS POST). Now might be a good time to re-suggest it? <hint, hint...>...

beerchug

-Eric

I had to do this recently for extend and retract on a cylinder. I used Terry's method but I needed to display the times on a Panelview so I needed to reset them each time. The best way I found was:

Ext Sol     Ext Sw.

---] [--------]/[----+---------|RTO 1|---

                     |

                     |           RTO 1

                     +--[OSR]----(RES)---



Ret Sol     Ret Sw.

---] [--------]/[----+---------|RTO 2|---

                     |

                     |           RTO 2

                     +--[OSR]----(RES)---

For those not versed in AB, the RES instruction resets a timer (or other thigs) to 0. The RTO is a retentave timer.

I did this to give the operator some feedback in setting the rate of the cylinder stroke as it was an air over oil system in a vertical orientation. The lines or something had been sized wrong and we needed more speed so we had to put the flow controls on the air instead of the oil . That way they could adjust their flow controls and check the time and also have a record for when components needed to be replaced or when the bored 3rd shift guy decided he could make the process better by fiddeling around with whatever knobs and adjustments happend to catch his eye .

ndzied1,

If you look at the first line after your ladder you'll see that it went off the screen.

Until such time that Phil fixes this problem, I suggest placing a single dummy character in the first line after a ladder, then hit enter. Then begin text on the next line.

BTW, the ladder in my post is not mine.

If you look at the first line after your ladder you'll see that it went off the screen.

Click to expand...

Strange, not in Netscape 4.7. But I have seen this with other browser versions.

Sorry for the wrong reference. The original code was Eric's.

I did use your <size><b> suggestions though

Thanks

If I wanted to do this, I would Start the timer when the first Solenoid was lit up.
Then when the Extended reed switch lights up, I would move the accumulated value from the timer into the N7 word.
Just make sure that your preset value is larger than worst case extension time.

Oh! I forgot, you might not know what one shots are.
Do a search on this site there is plenty of information on them.