timer

I have an application where I am using a PLC(OMRON) to index a conveyorthrough the input it gets from a photoeye. What is happening is that for every different part that the conveyor uses I have to manually change the TIMER on the PLC. Is there any way I could do this witout having to go and change the program by installing a rotary (potentiometer) like switch.

Hi

You can do two things if you uesing CPM model you have two rotary
potentiometers neer the communication plag you can use them but

be careful they very delicat.

you can use external timer you need one input and one output(the esey way).

and you can take two push buttons and create UP&Down system

you need to use @inc and @dec pay attention that you need to define higt limit and low limit other wise you may go out of control

if you want example send me youer e-mail and I will send you file.

let me know if you useing CX Programer or Syswin

I'm just curious what the exact sequence of events is. This may be a perfect opportunity for bit shifting....

I agree. A shift register would be perfect.
beerchug

If I understend the process well you have different parts on your
conveyor and they camming randomaly You may be need to use rotary
encoder and shift register . In that way you can measure the part in
pulses and transfer it to time.

A sequencer if it is available on your PLC may be the answer. BSL does not change the timer value each step. Try an SQO with a MOV time value for each step. Recent experience doing this with a SLC150 to micrologix conversion. After a little coaching from the whitebeards, it actually works well.

As Vetteboy indicates, more details on what is happening would be helpful. That said, if extreme accuracy is not needed and depending on the type of indexing used - for example, brake belt vs. air operated stop - a simple timer might work.

While the product moves past the PE run a timer, use a retentive timer in case the conveyor stops for a jam or shutdown. When the PE clears, save (and manipulate if needed) the accumulated timer value to use as the conveyor run time.

Just a thought.

I ouldn't say that extreme accuracy is needed. Another thing I want to clarify is that parts dont come randomly. If I start running one part it is usually run for a whole shift. I really like the idea of using a increment and decrement like switch. What instruction should I use.

@INC and @DEC. The channel will increment and decrement by one each time the leading edge of the button press is detected. If you do not use @ before the function, the channel will be incremented and decremented on each scan flag while ever the button is pressed.
I can see problems as you will not know what the setting is unless you output to a series of lights. Much better to use a BCD switch and you know what your setting is. Eg: when BCD switch is 1, move #30 (3.0 seconds) to DM1000. When 2, move #35 (3.5 seconds) to DM1000. Use DM1000 as your reference in the timer and not a constant.
Did you know that the latest CS1 and CJ1 can have the timer base set up as # (constant 0000-9999) or @ (binary 00000-65535 decimal)? Right click on the PLC and select properties to do it.
beerchug