blueheeler

It is an in house made hitchfeed using two pnuematic grippers and one push cylinder. And it operates from one solenoid valve. When the solenoid is energized the rear gripper closes, the front one opens and the push cylinder feeds the band of material. The oposite happens when the solenoid is de-energized. The die safety part of the circuit never worked perfectly. How could it? It depends on several adjustments by the operator. And the 10 presses are all set different. I thought improving the scan time might improve the accuracy of the settings. If the press is turning 90 strokes per minute and the scan time is 10ms, then the crankshaft passes thru 1 degree per 10ms scan. If the processor takes more than one scan to process the ladder program, then the settings are not that accurate. How many scans does it take to process a 200 rung program broken up into 5 subroutins and read the outputs from the HSCE module?

Let me try to clarify what we are doing. We use an encoder, TDC prox switch and HSCE module to monitor the position the press crankshaft is in. The solenoid for the pnuematic hitch feed is turned on at a certain position (degrees) and off at another. The die safety has a part ejected program and a part jammed program. The die safety part ejected program must see the cut off part cross the photo eye in the die within a certain window defined by two degree settings. The press stops if a part is not ejected. The part jammed program must not see a part using the same photo eye during another window defined by two degree settings. This window is near the top of the stoke and stops the press if a part is jammed. The photo eye sensitivity is adjusted by the operator to see the actual part as it falls and not the header that enters from the side and hammers a head on the wire strip that is the next brad strip ejected. I hope this helps everyone understand the problem.

Thanks for the suggestions everyone. Is there information available on arranging the program for faster scan times? The HSCE is used in the ladder logic. It also operates the hitch feed. It has several subroutines and production rate calculation subroutines have also been added. The press makes brads (finish nails). It hammers a head on the end of the wire band and then cuts the brad strip off. I'm ignorant of the mechanics of the press and will have to do some investigation to answer some of the other questions.

We are using a SLC500 with a HSCE module and a photo eye embedded in the die to monitor the 360 degree stroke of a punch press. The PLC checks to see if a part is ejected shorted after the bottom of the stroke and to see if the part is jammed at the top of the stroke and stops the press if it determines there is a problem. We seem to have a greater problem with die crashes since the stroke rate has been increased. The stroke rate is 100 strokes per minute. Are there higher speed PLCs available now that will do a better job than the older SLC500s? I would be interested in any other suggestions on this subject. Thanks.

Let me see if I have this straight. AB has a processor with a 1-shot statement named OSR. And they have another processor with a 1-shot statement that works the same as the statement in the other processor that they named ONS. This processor also has a 1-shot statement that works different from the OSR in the other processor and they named it OSR.

Is there any difference in the function of a ONS vs a OSR statement in Logix500?

I'm still having a problem with the PLS setting the outputs. I was able to obtain a copy of the example in the knowledgebase which was written for a 1500. I changed the processor to a ML1100 and the output mask HSC.OMB to account for the difference in the outputs and it still will not work. Since I don't have suuport, I went thru my distributor and a tech rep is currently working on the problem. I still haven't talked to anyone that has actually used the PLS function. If I can't get the PLS function to work correctly, I plan on using a GRT statement followed by a LES statement to create the windows that I need. The shaft moves approximately 1 degree every 2 msec. I was wondering what kind of inaccuracy I can expect due to the scan time of the ML1100 running a small program. The feeder is air operated and has a mechanical stop, so I believe I can live with a few degrees inaccuracy. Thanks for the help you have given me.

I had no trouble setting up the HSC in mode 7 so that it would increment the acc.. But I don't understand the PLS function and I have not been able to turn on the outputs at the HIP values. What I am trying to do is setup 3 windows based on the shaft position as shown below: 45 to 180 degrees Turn material feeder on and off with an output bit of the controller 200 to 260 degrees Check to see if part ejects with Photo eye. I can use an internal bit for this and top stop the press. 330 to 360 degrees Check for jammed part with photo eye. I can use internal bit for this and top stop the press. I don't understand which bits turn on at the HIP values or I don't have them set correctly. Thanks for any help that you can give me.

Thanks for the link. It looks simple enough, but to me a simple working example is sometimes worth more than an instruction manual. I always read the instructions when everything else fails to work.

I plan on using a ML100 and a 360ppr quadrature encoder to turn a material feeded on and off based on the position of the shaft on a punch press. Does anyone have a basic example similar to this application that usea the PLS Function and can be posted? I do not have a tech support contract and cannot get the answer I need from the knowledgebase. Thanks for any help you can provide.

I'm working on a project where we are going to pack parts coming off a press every 250 ms (240 parts per minute). I've been told that the scan time on the ML1100 will be a problem and that the Omron CP1H is faster. How does the speed of the ML1100 compare to Omron's CP1H?

Is the Omron's CP1H significantly faster than AB's ML1100. I'm working on a project where we are going to pack parts coming off a press every 250 ms (240 parts per minute). And I've been told that the scan time on the ML1100 will be a problem.

I have been asked justify buying AB when the software cost is so much higher than Omron. Can anyone give me anything to justify the higher cost of Rockwell's software? And if we were going to base the purchase totally on cost wouldn't PLC Direct be the better choice? I believe the PLC Direct hardware and software is less expensive.

Is it possible to supply the sinking output pulses from a Microlix 1000 to control an Automation Direct Surestep Stepping Motor Drive? Does AB have any PLC other than the Logix5000 series that will do this? Does anyone have have sample code showing how to do this? Thanks for any help.