I recently received a message from someone who had just purchased a used machine with a SLC-500 based control system on it.
Because most of his existing systems use simple relay controls, the new owner of the machine was reaching out to me about training on the SLC-500, as well as to ask several questions which all boiled down to, “Is the SLC-500 still viable?”
I believe the reason for that question was due in large part to the fact that when he tried to get support for the SLC-500, he felt the local rep was only interested in selling him an upgrade to ControlLogix.
So today's question is, “Is the SLC-500 still viable?”
To be frank, if you're building a new system today you should absolutely not be using the SLC-500. In fact, it's my opinion that any system you built in the last ten years should not have been built using a SLC-500.
While many of you may think that's an obvious statement, just a few years ago a company duped one of our local towns here in the Berkshires into buying a complete control system based on the ancient SLC-500 (ugh.)
That's not to say it's a bad product, or that you should worry about your installed base of SLC-500s, but you should be aware of a few things.
First, Rockwell makes very few new SLC-500s today, and they are expected to stop making all SLC-500 products in the coming years.
Second, you also need to be sure you know what and where your RSLogix 500 software licenses are, and consider getting a basic Rockwell support contract to cover your SLC-500 and RSLogix 500 if they're used on critical machines.
If you don't currently have SLC-500s in your plant, but you're looking to buy a used machine that has one on it, you'll want to take the following into consideration:
First, you need to be sure the machine runs!
No joke, I have seen more than one company buy a machine that does not run because the PLC no longer has the correct (or any) program loaded (i.e. the battery died, there's no EEPROM present or it was never updated, etc.)
Second, you need to make sure you're not locked out of the program because it has a password no one knows!
Third, while Rockwell has unfortunately doubled the price of RSLogix 500 over the last decade (it now costs nearly $2,900) if you're budgeting to buy a used machine that uses a SLC-500, also budget for a copy RSLogix 500 and a copy of my affordable PLC Basics course which will get you started with PLCs and RSLogix.
PS – I'm curious how many of you still have SLC-500's running in your facility?
If you do, please let me know by clicking on the comment link below!
- I haven't built a SLC500 project lately (9/2018) but I have two or three customers that still have the SLC500 robot cells still running with SLC5/05 processors. Just looked and one of those I did 10 years ago. It took me a long time to get them to change to a CompactLogix a few years back for newer projects.