carwash help please

[grayda]

Hi I new to plcs I have a very basic knowlegde of ladder logic I operate a Carwash (Tunnel wash) I need some help understanding how to use I believe [bsl] (bit shift Left) to control my outputs. I have a prox sensor on my sprocket detecting the cogs for a pulse I would like to take the number of pusles and store them for info on how long the vehicle is and where the vehicle is located in the wash. it takes 336 pulses(counting the true from false to true) from one end of the conveyor to the exit end I will turn on the first two outputs [o:0] & [o:1] as soon as the vehicle enters Photo eye. Output [o:0] will turn off when vehicle exits the photo eye, but I have to tell [o:1] to wait for the lenth of equip (10 pulses) plus the lenth of the vehicle which will be mesured by activating the photo eye and counting the pulses from the prox sensor. How do I store this info and retrieve it to turn on the rest of my outputs on down the line? (20 pusles later,25 pulses later and so on) I know you have to check to see if the conveyor in running [I:0 N.O.] and check to see if the photo eyes has been activated [I:1 N.O.] if so start counting the pulses from the prox sensor [I:3 N.C.] to determin the lenth of vehicle. I'm using a prox sensor because the conveyor changes speed depending on the weight of the vehicle it is pulling. so I can't use internal timers I don't think. Any help would be Thankful. I'm using A/B Slc 500 (1747-L511 5/01)

Dave Gray

 

[jimbo3123]

I guess I don't totally understand what you're trying to do, but hopefully I can still give you some ideas to get started.

Store the number of pluses that go by while the vehicle is blocking the photoeye (and thus the information about the length of the vehicle) in an integer file (ie. N7:0). You can then use that information to activate your output. I don't know where you were planning on using bit shifts, but it sounds like they wouldn't be necessary.

If you could put together a more complete sequence of operations then I could probably help with some example code.

 

[plc.doctor]

Why not use the bit shift instruction for each operation along the lenght of the car wash? You all ready have the pulses from the drag chain sprocket, and the number of pulses will remain the same from station to station. The only hard part to that would be if you're allowing for options like underbody wash, hot wax, silicone sealant, etc.. The Fifo Load / Unload instruction isn't available in the 5/01 processor.
It's sort of a shock to have some ask about an actual car wash, it seems like all the questions up till now are from students wanting solutions for their homework.

 

[grayda]

I was told by another plc tech that "bsl" would be the way to go but he did not have time to explain how it works (IE: File # Control # and Address) I know I have to assign these # but I don't know where to put them or how to acess them back when I need them. and yes I do have pay waxes and and a control to cut off my tall side brushes in case of an electric antenna won't go down is this going to cause me problems??

 

[ebram]

I'm in the same situation as the original poster. What type of PLC are you intending to use?

 

[grayda]

I'm using A/B Slc 500 (1747-L511 5/01) with 16 Inputs & 16 Outputs
P2 power supply


Dave Gray
Valdosta Kwik wash Inc.

 

[ebram]

Does it have the ability to be progranned with windows?

 

[grayda]

Yes I'm using Rslogix 500 english ver.3.01.09 I'm using Windows XP at home to experiment with the program but I will be using Windows ME Or Win 98 sec. edit to do the actual programing and uploading.

 

[plc.doctor]

Here is a quick example to get you started with using the BSL instruction. It's using the number of pulses for the total length of the chain, but you can use more BSL's and have them hand off from one to the next.
[attachment]
The counter instruction counts 10 pulses when the vehicle enters the process and should stay done until the next vechicle enters the system.
There is an explanation of the BSL in the intruction set reference in the help section of the menu bar of the RSLogix software.

 

[grayda]

Thank You PLC Doctor I have already got started from your example.

 

[grayda]

How does "c5:0/dn " know to count 10 pulses and then reset? Do I have to tell it to?

 

[jrwb4gbm]

Look at the SLC instruction help in RSLogix. Look up CTU and RES.
I know the help is a little confusing. Yes, you would need a RES on a separate rung below your CTU counter. You should also put what you want the counter to do in rungs in between the CTU rung and the RES rung in most cases.
Sid

 

[grayda]

Thank you on the way to work will check out the info

 

[grayda]

This Is what I have so far

B10(mitter) needs to be extented or lacthed for the 60 pulses + L.O.V. vehicle then needs to be ready for next vehicle. (and then so on)
Am I on the right track or do I I need to Back-up and start again?

Please keep in mind I have about 3 weeks of training (reading post and tutorails)

I-0: conveyor motor running

I-1: photo cells [2 photo cells spread 3” a part] when both photo cells are blocked will give 1 signal (to detect vehicle entering carwash)

I-3: Prox switch (counting cogs to give pulses)

Definitions:
L.O.V. = Length of Vehicle (total count of pulses while photo eyes are blocked by the vehicle)
Pulse = 1 cog on sprocket
Total length of carwash tunnel = 336 pulses
1’ = 5 pulses (approx.)

O-0: Foamer activated by “B3/0” stays on as long as vehicle is blocking photo eyes = L.O.V.

O-1: W.S.Mitter activated by “B10/1” stays on for 60 pulses + L.O.V.

O-2: V.H. Brushes activated by "B11/65"(after “65 pulses”) stays on for 10 pulses + L.O.V.

O-3: Side Brushes activated by "B14/68" (After “68 pulses”) stays on for 10 pulses + L.O.V

THANK YOU

 

[grayda]

Help see previuos post please