Hi fellas,

I need some help. I know nothing about the MicroLogix family of controllers. Can you give me a brief comparison between the MicroLogix (1500 in particular) and SLC 5/04?

I ask because our strapping machine OEM has presented us with an proposal to upgrade our strapping machine from steel to plastic strap. Their proposal includes adding a new MicroLogix 1500 to control the new strapping head only. Our existing SLC 5/04, which now controls the entire machine including the existing hydraulic steel strap head, would still be used to do everything else.

My issue with this is that we don't have any MicroLogix on site so I'd have to buy added spares and it would be a one-off oddball in the facility. I'm also not thrilled about having to watch 2 controllers when troubleshooting. I'm sure the techs wouldn't like this either. Compound that with it being a totaly foreign controller to us. Our techs are very talented but I just want to minimize complexity of the system. I'd like to propose to the OEM that instead of using a new MicroLogix controller, we run the head with our existing SLC via RIO and Flex IO.

Reading through the AB web site I ran across the 1747-SN module (Remote I/O Scanner Module). I've never used one. Would this suffice to talk to RIO Flex IO? I'd welcome any insights into it's use or feedback on my idea in general. Thanks in advance.

The ML1500 uses the exact same software as your SLC uses. So the learning curve is nil!

You've already identified the biggest difference - the physical hardware. It's obviously a different set of parts to stock.

The OEM probably recommended doing it that way because they could bring in an all-new, totally contained system that has been pretested before it arrives at your site. To move it over to a SLC5/04, all they'd have to do in the software is to reassign the processor in the configuration.

Or they could certainly write the new software and add it into your existing controller, then use either flex logix or SLC-style IO modules -- via the ASB module you've identified. Honestly, this would (most likely) be my personal preference if it were my system. This would require a longer startup because all of the hardware installation and much of the wiring would have to be done on-site, but IMO it would be a simpler system to maintain and troubleshoot.

You're right. The oem's justification is for ease of installation.

I'm going to propose that they leave the real estate for the PLC in the enclosure empty for us to install our Flex IO. We could then configure and commission the RIO connection before full installation and commissioning happens.

Question: Can a MicroLogix program file be imported and merged into an existing SLC project? My SLC project is already segregated into subroutines, one for each part of the machine. Since their plc program is only for head control it would just be a matter of importing their file, readdressing some stuff, adding the JSR for their file and disabling the existing head program file jsr.

code is the same, you can copy and paste, but the address range may be overlaping with your PLC (search and replace can fix that). Newer ML1500 can have L data tables (like N but 32-bit integers) and one shot uses different mnemonic (again simple search and replace). also you can keep it, just link them through DF1. main complaint with ML1500 was lack of online editing but it's not that big deal since it's smaller plc anyway.

Why not leave their "real-estate" in situ and just replace the cpu with a remote i/o adapter ?

You mean reaplce the MicroLogix processor with a RIO adapter and stil use the Micrologix IO? That still means I would have to buy new spares and that IO hardware would be unique to that installation.

How 'bout have them install SLC I/O then they can develop/test the code with a test-SLC. Give them a copy of your existing code so they can make sure there are no overlaps. Then they can build/test the machine at their site, come to your site and install system, connect RIO to your existing SLC, dump new program into existing SLC.

If we were to use SLC IO in the new remote enclosure, what would I use as the RIO adapter in the remote chassis, a DCM? But a DCM requires a processor to read from it, does it not.

To use SLC hardware in the new expansion unit you would need to add a 1747-SN RIO Scanner to your existing rack which contains your CPU and then place a 1747 ASB in the remote rack which is in the new equipment. THis would give you the ease of having the same hardware and if your OEM has a "spare" SLC CPU he can fully test before coming to your site. The Literature Library has links to both the 1747-Sn and the 1747-ASB module.

Thanks for the info Bob.