Today we dig into our mailbag for another edition of “Insight’s Inbox.”

Reader Question:

1747-PICI’ve run into an issue for which I would like to ask your opinion.

Here in our plant we have SLC-500, specifically a SLC-5/03, which controls our material handling system.

Whenever I connect to the SLC-5/03 to attempt to make a change, I kept getting a “Fatal Error.”

I’m using a 1747-PIC with my Panasonic Toughbook running Windows XP Service Pack 3.

Insight’s Answer:

SLC-503-FrontI think the problem may be you are using Windows XP Service Pack 3.

If memory serves me correctly, most (if not all) versions of RSLinx do not support the 1747-PIC on any operating system past Windows XP Service pack 2.

As an alternative, you could try to connect to the 5/03 via it’s channel 0 DB9 port, using either a 1747-CP3, or a standard null modem cable.

Just keep in mind you’ll most likely need to stop and remove the 1747-PIC driver in RSLinx, and add the DF1 full duplex driver in it’s place. This is because the 5/03’s channel 0 port is by default set to DF1 Full Duplex.

If you want to know for sure what this SLC’s channel 0 communication port it’s set at, open the last program you uploaded from this PLC, and look at the channel 0 communication settings.

You could also try Rockwell’s new 1747-UIC, which is supported on newer operating systems. I recommend the 1747-UICC13 which is a bundle of 1747-UIC and C13 cable, since using the wrong cable (like an Ethernet cross over cable) with the 1747-UIC will permanently damage it’s RJ-45 port

There are also low cost third party UIC cables available, and I’ll link to one below:

Update: If you have your own question you’d like to ask, please post it as a comment on a related post here at

Until next time, Peace ✌️ 

Shawn M Tierney
Technology Enthusiast & Content Creator

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Shawn Tierney



  1. Hello. I have a SLC L543 that is running out corn dryer/elevator system here on the farm. It has faulted out and I cannot communicate with it. I have tried factory reset and removed battery over the weekend but it remains locked up. I have tried a spare SLC processor but cant seem to comm with it either although I can with yet another SLC that is working properly.
    I’m using windows xp with RS linx.

    • Good morning Gerald,

      First, can you tell me a little about your Windows XP PC? Is it SP2 or SP3? Does it have a built-in serial port, or are you using a USB to Serial converter?

      Which version of RSLogix and RSLinx do you have? What cable are you using to connect to the SLC? If it’s not an A-B cable, what is the pinout? (i.e. is it a null modem serial cable? 2-3, 3-2, 5-5)

      As far as the offline files you have for the PLC, when you open them what are the communication settings for Channel 0?

      Next, can you tell me a little about your SLC-5/04? Does it have a memory module installed? Is the light flashing RED or solid RED?

      Please include anything else that you think would be helpful too!


      Shawn Tierney,
      Instructor at


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