First program

Project is an auto sampler, pnuematic ram extends every 15 mins and then retracts with the option if an immediate sample is needed a button is pushed and the ram extends 4 times. my question is this the program iv'e written seems rather long and convuluted for such a simple job!(and there is one bug in it that i can see!) is there a better (simpler)way of doing this task? the attached file is rss just change the extention.

I cant get the zip file to open? Did you test the zip after you posted it? Error is an "invalid archive".

Thanks, Mike.

zip file

Yes just tested it again, download then change extention to rss and open as normal

Oh... so it's not really a zip file... I missed that in the first post, sorry..

Anyway, I dont have RSlogix, or any AB sofware.. so much for that..Maybe you can do a print out to a pdf file so we all can see it?

change extention to rss

OK...I know its late, but how the heck do ya change the extension? Been trying off and on for awhile now but no luck.

Bob

1st download the file (right click -save as) then right click on the file on your computer and choose "rename" then change the extention to .rss.

duh... banghead

need I say more?

PDF file

OK check this out.(neat bit of sofware this for the price(zilch)).same deal just change the extention to pdf !

safeties?

I took a quick glance at the source code you provided and noticed that you had no safeties installed. Keep in mind that Rams have some
rather stingent safety regulations. In occupational health and safety they are described under press regulations. Usually require a two button control where both have to be pressed in order for the operation to work. You will pobably need this only in the manual mode provided there is no possible way for personel to access the ram area in auto mode. However in auto mode you also require a safety input. I'm still looking at your code

I dont think the OSHA press requirements apply to all uses of rams, this is not a press.

I agree that it seems long and complicated for the application. I believe you could do this in one LAD with fewer rungs. Create the auto sample sequence at the beginning....I havent quite determined how you start the sequence but will keep looking. The auto sample sequence should be a loop that initiates at the preset time (approximately 10 or 15 minutes according to your code/statement).

You dont necessarily need to create a separate manual mode for the request for 4 samples. Just use the PB to initiate a sequence to extend the ram X number of times, when this is initiated the bit used to start it can turn off the auto part if needed.

Then create your alarm(s).

This could all be in separate ladders but I dont think there is a need for that many rungs just for the application itself.

I will look harder at your code then try to create something simple (its all I know how to create) and post it for you to view.

Agreed that however is a determination that he would have to make. The regulation applies if any part of the ram is accessable to an operators hands. If so then they do apply even if it isn't exactly a press. Our plant came to that realization after our wonderful electricians decided to bypass the PLC on our loin loader. Whos operation merely pushes a loin into a bag to be cryovaced. Further research and some phone calls to OHS made them realize that it did indeed require the two button start operation.

At this time I will assume this to be a training exercise more than a real world application. The use of 2 hand controls I want address unless it becomes obvious there is a need.

I am not sure I fully understood what you are doing but from the description I attempted a program that would initiate the warning light 3 secs prior to the ram extend, the ram would extend for 10 secs automatically. If the Manual request PB is pushed the auto sequence is disabled until 4 samples are take...ie the ram extends 4 times. This program is basic and only 6 rungs but maybe it will give you an idea of the options you have. I am sure it has mistakes because I am not a real programmer nor do I play one on TV.

I did the same thing you did, renamed it a zip file.

OOOPPPSS I know it has a mistake...I didnt initiate the warning light with the manual request. That shouldnt be but 1 more rung at the most though. Also not positive I did the flip flop right but it is close.

Unfortunately the second program does not run the full operation that
the original does in auto he appears to have a 50 sec timer after start is pressed. then a 3 second warning light on output 2.
followed by a 3 second cylinder output. deactivating the warning light after 3 or 4 seconds In manual request he has a 3
second warning light. activate output 2 for 3 sec off for 3 sec repeat 4 times. RKAY could you let us know what timing you require in full?

I wasnt trying to actually match the timing just show another way to make the cylinders extend for a time period using one timer...ie less rungs. The warning light also used the same timer, add an LEQ and it also can be turned off at any point.

I used a flip flop to cycle the extend for manual requests, the counter determines how many times....the counter preset can be setup to use an N register so it can be changed via an HMI etc.

The application seemed simple enough. Extend the cylinder every 10 or 15 minutes....this time could be set by use of a register and am HMI or just preset. Turn on light when in auto and turn on warning light when about to extend.

I "think" I basically fulfilled those requirements except for incorporating the warning light in manual which could be done by adding a branch to warning light rung. I used 6 rungs to basically do what was stated....albeit not perfectly. If I am correct with my code in AUTO the ram will extend for 10 secs once every 10 minutes. The warning light will come on 3 secs prior to the extend and stay on until the timer times out and cylinder output goes off, then timer should start timing again....the timer values can be whatever. The manual request PB when pushed stops the AUTO sequence and starts the flip flop timers that will extend the ram and hold in place then retract...wait then extend again...then repeat until counter has seen the ram extend 4 times. That part may need some rework because it may interrupt the last cycle. Did this kind of fast and did not test it but basically I have done things similar so should be close enough to offer some ideas.

Just offering simple ideas (which I am good at) to assist in learning other ways to accomplish something.

yeah i figured that out after I posted