quick help with slc 5/04 OSR

2004sk4 · Nov 4, 2005

I can;t seem to make the osr bit work correctly on a slc 5/04.

I have a analog 0-10 volt input which reads a speed pot mounted to the machine. I am trying to make a start sequence so as soon as the pot is moved it will automatially jump to the preset value from the touch screen until the pot is turned up past that. This will prevent needles from being broke by trying to start the sergers to slow. The problem is that i want to only use this preset when starting and not when turning the machine back down. I need the full range when turning the machine back down but the code is holding to the preset value

i can;t seem to figure a way the osr will work.

f8:28 is the scaled starting fpm
f8:29 is the scaled max allowed fpm
N7:80 is the max rpm at 10 volts

the rungs in question are main file rung 3-9
the scaling is on rungs 14-15 on the main file

CroCop · Nov 4, 2005

I made an assumption that F8:22 is the speed refrence. If needed, change it to make it so. Check out the attatchment. I commented the rungs.

2004sk4 · Nov 4, 2005

f8:22 is the displayed voltage on a setup screen on the touch screen. It scales 0-32767 to 0-10 volt by the screen. The start speed setting is set by the from ts and goes to rung 16 which makes a scaled output according to the max rpm n7:80 Is there certain rules to osr when using them with compare functions Rung 17 is the max allowed feet per minute scalling function . This is a way to keep the operators from overspeeding the serger machines(lots of damage can occur over 2800 rpm.

CroCop · Nov 4, 2005

A few questions

2004sk4 said:
f8:22 is the displayed voltage on a setup screen on the touch screen. It scales 0-32767 to 0-10 volt by the screen.

Why do you have a 0-10 Volt on a HMI? Wouldn't it be easier to show an engineering unit, ie velocity, distance, etc?

2004sk4 said:
The start speed setting is set by the from ts and goes to rung 16 which makes a scaled output according to the max rpm n7:80 Is there certain rules to osr when using them with compare functions

Yep. OSRs OSR everything that precedes it. If you want to check the compare once, put the OSR after it.

2004sk4 said:
Rung 17 is the max allowed feet per minute scalling function . This is a way to keep the operators from overspeeding the serger machines(lots of damage can occur over 2800 rpm.

What is a serger? I'm curious, I haven't heard the term before.

Marc

2004sk4 · Nov 4, 2005

The f8:22 is only used for the maint rpm setup screen. i plan on using it to run all the machine to 10 volts and entering the value from a hand tach into the f8

40,50,60,70). I have some simple math which take care of the gear ratios. The result of the math give me a estimated rpm per voltage on each machine. The only thing the operator will see is the calculated rpm. I know this doesn't accoount for belt slippage but the project didnt' have enough money left for high speed counters cards . The math for the rpms is main program rung 20-39 32-39 are used to not div by 0 which the plc doesn't like.

A serger is a belguim made machine(TITAN) that sew thread on the edge of area rugs.

CroCop · Nov 4, 2005

That's cool man. Unless it is critical, you should be just fine with the estimated values.

Is there quite a bit of automation in sewing? Forgive my ignorance, I just haven't been involved with that industry at all.

2004sk4 · Nov 4, 2005

The current machine setup is very outdated. It uses a paddle with 2 prox switchs to move the sergers (one on each side) in and out. The machine is currently controlled by 3 dynapar max speed jr speed controllers. We are putting a touch screen on that eliminate all or the above. The paddle are being replaced with high resolution banner photo eyes and the speed setpoints will all be on the screen. As the Prices for raw materials rise the more automated we will have to become.

Will i need the osr to be on the grt compare function on rung 7-8 to make the osr work on the start up but not the stopping. What will reset the osr.. i am used to micrologix where u only have ons functions

What industry are you associated with?

CroCop · Nov 4, 2005

Here's the trick.

The OSR will be true when there is a false-true transition. When the rung value goes false, and then goes false-true again, it will be on.

The trick to what you want to do is OSR the first on and give it a minimum speed. After the minimum speed is met with the pot, then shift into the pot value.

If this doesn't make sense, I'll give you a quick ladder example.

CroCop · Nov 4, 2005

Oh, right now I'm in gas & oil services industry. See www.intellipipe.com for a description of our product. I'm doing the plant automation for a transition from R&D to full blown production. Talk about stressful! They want to triple their output at least, and want it all now. Good times, though, a great place to work.

rsdoran · Nov 4, 2005

If an HMI is going to be used I would just eliminate the pot and do it with the HMI. In other words you can just enter a value and it goes there over time, you control/limit the ramp time and speed as needed.

The RMP instruction would be nice but I think an ML is being used so that is not an option.

I did not look at the program but using an OSR with a straight compare...ie N7:10 is equal to 5 can create problems, over or undershoot and the rung may never see the specific value.

CroCop · Nov 5, 2005

He's using a 5/04. The OSR is used to check a value coming off of a zero.

I think he'll need to do it a little different, because he's checking an input coming off of zero. I've never seen a 0-10 exactly at 0 on the low end, but that's me.

rsdoran · Nov 5, 2005

I guess I should look at the program. I dont think it matters what the value is for the analog input...ie 0-10, 4-20ma etc etc, the fact is it will represent an rpm or something similar...ie zero rpm to max rpm. The 5/04 could use the RMP instruction and take it up or down to any speed requested over time. This would allow you to control/limit the max speed and how fast it gets there. It could also eliminate the need for an analog card.

Its just something I would consider.

2004sk4 · Nov 5, 2005

The operators are used to the speed pot is the main reason. Also the operators like the speed pot becuase they can turn it down fast if a problem arises. We had to buy a analog card anyways becuase of the high resolution banner mini array photoeyes are 0-10 volts. . I notice the low end of the analog input too.I made it look (>1 enter 0 in floating point) (<1 enter input in floating point)to overcome this. The program to runs properly on the starting and the max fpm. I am wanting to be able to skip the start frg rung once a higher speed has been reached. IF i osr the les then function and latch a bit and then unlatch it when the grt function is activatied. Will this solve the problem.

thanks for all the advise

CroCop · Nov 5, 2005

Easier Way

There's an easier way to do this. See the attached file.

It uses simple compares and a latch/unlatch bit.

I changed memory locations, and just gave very simple names to variables.

Marc

2004sk4 · Nov 5, 2005

Thanks for the example. what would i use to unlatch the bit. I am guessing the leq f8:0 0 --utu b3:0/0
thanks

quick help with slc 5/04 OSR

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