plc-5 slc 500 compatibility

D

Thread Starter

dj

are PLC-5 and SLC 500 file compatible?

i want to establish comm between a third party device wich only supports PLC-5 connectivity through DF1 protocol via RS232.

can i use an SLC 500 instead of a PLC-5?

what are the main differences between both types of controllers?
 
S

ScienceOfficer

dj---

It's highly likely that you can establish communications between the third party device and the SLC500, but you haven't provided enough information for me to promise you it will do exactly what you want. There ARE differences in the addressing between PLCs and SLCs.

I suggest that you ask the manufacturer of the third party device for assistance and possibly sample ladder logic. You probably won't be the first to ask this question.

Hope this helps!

Larry Lawver
Rexel / Central Florida
 
L

Lynn at Alist

PLC-line differences in DF1 is one of the skeletons in AB's closet. There are at least 4 "groups" or flavors of commands:
- PLC2 or CIF (looks a lot like Modbus - read/write 1 BIG table)
- PLC3 (read/write data blocks of various file types)
- PLC5 (like PLC3, but offers more complex/flexible 'addressing' to data)
- SLC5 (most of the power of the PLC5 commands, but simplifies the addressing into fixed fields & is file/table oriented only)

I personally like the SLC5 style "protected logical rd/wr with 3 address field" & implement them first in new code.

A new SLC5/0x should be able to answer any common PLC2/PLC3/PLC5 command. Some of the MicroLogix line ONLY handle the PLC2/SLC5 commands completely. If you look in the DF1 manual at www.ab.com it indicates generally which PLC like which command. This document is out of date -
even if it says a SLC5 or uLogix won't accept the command, you may find that they now do.

- LynnL, www.digi.com
 
I actually ran into a problem in that respect. A third party device reported
network failure when connected to a Prosoft DF1 card, while reporting no
network failure when connected to the PLC port itself. Both manufacturers tech
support people stated that AB does not implement the DF1 standard completely.
Prosoft apparrently decided to implemnt DF1 per the standard while the other
manufacturer used the AB variant. The only difference I could tell was how it
handled network tests, as actual data transfers worked fine.

Bob Peterson
 
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