Help with SIMATIC TI335 shift register

[eternalphoenix64]

Posted previously but had the wrong info, hoping to get new advice.

Being a mechanical engineer, I'm not very experienced with PLCs, and what little I do know is in RSLogix. We have a SIMATIC TI335 PLC and are currently using the shift register to track one type of reject condition (see attached image). In this process, any time the machine stops, there will be 3-5 items on a section of the machine that will have defects and need to be rejected, and we're working on automating this process. I have a grasp on how to get the wiring done and the mechanical side of things, but I need help with the syntax/code for the ladder logic.

The shift register locations for the defects are most likely not going to be 0-4, but that may be an option with modifications to the location in the shift register for the reject to fire on. The current rungs are placeholders for this work, but need to be refined. I can do the input side pretty easily, it's doing the output that has us stumped, and Google has not been my friend.

Pseudo code: "whenever the machine stops, make these X specific locations in the shift register be a 1"

Thanks in advance.

 

[gclshortt]

What you want to do is use a move command to move the value "FFFF" into each of the shift register words. This will turn on every bit in the shift register.

Regards,

 

[eternalphoenix64]

But I don't want to reject everything.

For example, the items to be rejected may be something like 5th, 6th, and 7th on the line, but I don't want to reject items 1-4 that are good product, or items 8-16 after the reject that will also be good product.

Even if I did want to do as you are proposing.... I have no idea how to do it.

It's kinda like being given all the materials to build a cabinet, and I can maybe sorta kinda figure out which pieces go where... but I don't know how to use a hammer or screwdriver.

An example rung for the ladder logic would be exceptionally useful. If it's just a matter of choosing the correct hexadecimal word and moving it into the correct address of the shift register, only half of that is easy. I can convert between binary, hex, and decimal all day on paper. But doing that in the PLC and affecting the shift register are tools I don't know how to use.

I should also mention that I do not currently have access to the software for me to tinker with it and figure this stuff out the hard way, and I have never seen the UI for the TI software.

 

[Dravik]

I haven't used this PLC before but the manual I found says that based on your Screenshot you currently have a 12 position bit shift register.

SR400 - SR411, all of which are contacts(bools).

So you could, for each 'position'(let us say SR405, or the 6th position in your register) you want to reject at, do this
------|XIC SomeRestartContact|-----------(SET SR405)-----

SET is a command that will 'latch' the bit on until something else unsets it.

You'll probably need a one-shot or something to prevent that line from executing every scan.

 

[Dravik]

Also, I *think* you can program those with DirectSoft from AutomationDirect. I would give them a call and double check.. but it is a quite reasonable cost if so.

 

[eternalphoenix64]

Thanks. That's probably (hopefully) exactly what I need.

Can you post a link for the manual you found? I wasn't able to find one.

 

[Dravik]

Thanks. That's probably (hopefully) exactly what I need.

Can you post a link for the manual you found? I wasn't able to find one.

https://cdn.automationdirect.com/static/manuals/d3user/d3user.html

That's for the DL305 series(including the DL340 which is the equivilent of the 335.

 

[eternalphoenix64]

Do you think this would work? (formatting got wonky.... the reject PB is an OR rung around SR4XX and SR4XX+X)

Start Enable
|------|/|----------(SET SR4XX)----|
| Start Enable |
|------|/|----------(SET SR4XX+1)--|
. .
. .
| Start Enable |
|------|/|----------(SET SR4XX+X)--|


Along with

Start Enable SR4XX SR4XX+X
|------| |---------| |----|/|------(Bad product reject)--|
| | | |
| | Reject PB | |
| |-----| |----------| |

And

Start Enable SR4XX-2 SR4XX+X+2
|------| |---------| |----|/|------(Reject Belt Motors)--|

The last line is designed to turn the motors on for a separate conveyor to carry the bad product away to a reject collection for later disposal. They need to start before product gets there to get up to speed, and stop long enough after that to clear the reject system.