Learn to make on-line edits.
Not all of the SLC/500 processors support on-line edits. The 5/03 processors and above (i.e. 5/04 & 5/05) support this.
As Nachtwey mentioned, the strict 'programming' probably won't be the biggest issue if you can think
logically.
.
Other 'little' issues could be a mystery at first, such as communications with the PLC, downloading/uploading, how A-B puts its own spin on communications but uses industry standard sounding names like DH-485 vs. RS-485. What is the difference between RUN mode and REM RUN mode? Why does the EEPROM overwrite my program every time I cycle power? Those of us who have been using AB for a while come to take these things for granted. We have built up the inventory of knowledge, cables and other things (like the ubiqitous PIC, the ungodly expensive PCM/K card...)
When we got started, A-B did a lot of direct support and our local A-B office was extrememly helpful in setting things up. Now it seems they have pushed their support to one of three channels:
- Local Distributers
- A-B / Rockwell Web Site
- Paid Support and/or Upgrade Contracts
If you have a good local distributor they
should be able to bring a small demo unit out to your site to go over basics with you. They
should also have larger demo stuff set up at their office for you to see or get you into the local A-B office to see their demos. They
should be able to help you spec out your system (if you have a good understanding of what the system needs to accomplish and what hardware you need to interface with). Your first step should probably be to contact your local distributor to see how much support you can get.
If you are a one man show and bidding against established outfits, the startup costs can kill you (hint: the programming software aint $99 and the cables aren't free...come to think of it, nothing from AB is free except the doughnuts at the seminars
). In that case, you probably need to ask yourself, is this something I want to get into and eat the startup costs or is this a one-off opportunity. Maybe this is an in-house project? You mentioned
modifying an existing program
so it might be a 'fun' diversion from your usual grind... you might even like it better than what you are doing now????
There is one other thing I'd like to mention and that's is the added responsibility of programming devices with moving mechanics which people inevitabbly come in contact with. Depending on the complexity of the system, if
you the programmer does something wrong, someone could get hurt or even die! Although I know of some programs that might make someone want to kill themselves (one that starts with 'win' and ends with 'doze' comes to mind...), I don't believe any strictly software system has done any bodily harm. You will need to know and follow the applicable safety standards for the system you are programming.
Please don't think I am trying to discourage you. We are small shop and I have many tasks and I find PLC programming to be my favorite by a long shot. I just want to let you know what you are getting into.
