Replacing a GE Fanuc with a SLC5/04

[jld30]

I got a job out of school and my boss came up with a project to get my feet wet with PLCs. We have a 175 ton hydraulic press that has a GE Fanuc 90/30 that is in very bad shape, The task for me is to replace it with a SLC 5/04 and then add a method to control ram depth to the PLC also. So far I just went line by line with the program from the GE and wrote it in Allen Bradley, but there is a couple of lines that GE uses a TMR timer in a Latch Sequence that I am not sure how it works and how to do the same thing in the SLC. It looks like a OTU and an OTL but I do not understand this TMR timer unless it works like a oneshot does in a way.
Thanks Joel

 

[Christoff84]

I don't know GE, but from what you say it's probably the timer's DN bit (in AB). If you can find the actual timer somewhere, have a look and see if it makes sense for the line to latch when the timer is completed.

 

[Steve Bailey]

GE's TMR instruction works like AB's TON. GE's TMR does not inclue a .DN bit. The coil instruction to the right of the TMR serves that function.

GE's -(S)- and -(R)- instructions are the same as AB's OTL and OTU.

 

[jld30]

Thanks, that makes sense now! Any Ideas on how to aproach the depth control problem? The OEM was mechanical and broken also. I found a Linear Scale and HSCE input output card, not sure if they may work or if that is a good direction.

 

[sthompson]

GE's TMR instruction works like AB's TON. GE's TMR does not inclue a .DN bit. The coil instruction to the right of the TMR serves that function.

GE's -(S)- and -(R)- instructions are the same as AB's OTL and OTU.

Steve:

I bow to your much greater knowledge of GE. However, I thought the GE -(SM)- and -(SR)- were a closer equivelent to the AB OTL and OTU, because the retained through a power failure or Stop to Run transition. While the Instruction Reference Manual does not specifically state this, I gathered they do not retain their state through those circumstances.

Stu....

 

[Steve Bailey]

Stu, you're correct. -(S)- and -(R)- are GE's non-retentive latch pair. -(SM)- and -(RM)- are retentive.

 

[Christoff84]

For the depth control I'd look at a linear transducer, the ones I use on our hydraulic presses are from balluff. But it does depend on how fast and accurate your control needs to be.

 

[jld30]

You guys are awesome! This press moves pretty slow and he is doing it by eye for now so there is room for some error, we are bending sheet metal and need to be able to adjust for changes in it.

 

[RussB]

Also look at MTS and Turck for linear transducers.

 

[jld30]

Update

I wanted to say thanks for the help and let you guys know it turned out. This plc has been a side project till I get to work Monday to find out the the one it is to replace has died. The one I had on the test bench is now installed and after tweaking some timer issues " I was guessing about the GE timers" It is running great.