AB PLC2 to ???

We have around 15 nos. PLC2.

Out of this most of them are mini PLC2/15 or PLC 2/15.
Three are PLC 2/20
The above PLC 2/15s are in Old chasis 1771-AD)
Two nos. PLC2/17 ( with 1771-A4B chassis)

I went through all the program, they all use simple instruction.

Only one PLC2/17 used FEM instruction.otherthan that everything use simple NO and NC,timer and counter, put and get instructions only.

Now we want to replace all or one by one all PLC.

Should i go to PLC5 by using existing I/O board , but buy new cpu, new powersupply, new chassis( some PLC 2 used 1771-AD chassis) and these are not supported by Enhanced PLC.
I think PLC 5/20 will be economical option. But i donot know how long it will be supported.

The i have SLC and micrologix.

IN my view Micrologix will do the job. But i would have to make new wiring. But If i use existing wire then wiring will be little bit difficult in new Micrologix whose terminal are already small and my wire size is big (as it used PLC 2 and there were enough spacing for big wire size in its terminal)

I belive that i can purchase whole micrologix CPU, I/O and power supply at the price of one PLC 5/20 CPU and it compels me to go in Micrologix direction.

What will be your suggestion.

Eurotherm controls 2500 System

Does any of you guys using or heard about this controller from Eurotherm controls. www.eurotherm.com

We just have one in our plant with our new machine for temparture scanner. It just scans various Temperature probes and annunciates / trips the machine depending upon the set value.

The commissioning engineer told me that its a PLC and it can do more PLC job also.

You have any experience on these product and how good it is. What about the programming language (Easy or process like). I saw it and it looks like process instruction. Realy did not understand it. But he said its one of the easist.

As we are about to order one more machine from the same supplier and he insists for eurotherm products only.

Thanks

change to some brand

Hey Samie,

I would suggest going to the micrologix, since they are all ready starting to phase out the plc/5 series, also. Just got done with a job where they had quite a few plc2's, and believe me, it's a bugger to find power supplies/processors... The logix should also handle any instruction set that the plc2's offered, just remember that the 2 is in octal...

Hoot

Depending on size of application and networking I would not
recomend the micrologix because it's lacking online editing.
Do you really want to migrate 15-20 PLCs and then run around
when something is stuck and you cannot even edit?
Sure editing can be done offline and it takes only a minute
to download but your process was stcuk in certain position
or sequence and download will reset all to whatever was
in data files...

(just an opinion...)

Samie

We've changed out one PLC2 and replaced it with a SLC5/04 without any problems. I've got one more PLC2 to replace and I'll probably replace it with a 5/04 also. If you're worried about longterm support you might want to consider going to one of the Logix family of processors, ie FlexLogix, ControlLogix, etc. SLC's from what I hear up here will be supported for about 12-15 more years.

Dave

Thanks

Thanks Hoot , panic mode, Dave foley

Our biggest worry is the product support.

Whatever the PLC model we choose now it should be available for another 15 years atleast. Otherwise i will be in trouble.

Yes. We are planning to replace all the PLC 2 (approx 15 nos. all in working condition) to a new PLC model which should be supported and easy to maintain.

I really donot know what we are going to do with all the 15 nos. CPU,power,rack,I/O modules etc.

First i was thinking about SLC 5/04 only, but i belive it would also be phased out and comparitively micrologix 1500 family will be alive as its I/O is being used in CompactLogix system also.

I am planning to go for Micrologix 1500. Yes i cannot do on-line edit. But our program is almost fixed over the past 20 years and i belive we will not have any change in our program and hence micrologix 1500 will be economical.

My other issues is that we use some fancy cards in PLC2 chassis but i am not sure whether the below cards are available in Micrologix or SLC family.

Cat no.:1771-IT (true dc input)
Cat no.: 1771-ID (isolated input)
Cat no.: 1771-OD (isolated output)


Thanks

My local AB rep tells me that the Micrologix 1500 processors made later this year will support online editing. Don't let that shy you away from this platform.

samie,

Here is another option. Buy you a PLC-5 from E-Bay's WEB Auction. There are many new ones on E-Bay for practically give-away prices ($200-$500 for a complete system). The PLC-5 will be around for a long time yet, and as you noted, your Input/Output cards will all fit in a PLC-5 chassis. Then you will have no problems with the wire sizes. With the money saved, buy the RSLogix 5 programming software, which is an updated Windows-compatible package for the old PLC-5 processor. The program conversion will be a lot easier than going to a Micrologix. (Yes you will have to do some conversion, no matter which processor you upgrade to).