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Thread: All 5/03 to micrologix

  1. #1

    All 5/03 to micrologix

    I recently got a SLC 5/03 and built a simple board with a few lights and toggle switches. I’m currently in school for Fluid Power and Motion Control and was hoping to farther my skills in PLC programming. I am however having trouble getting my PLC and laptop to communicate via RSLinx. I currently have a RS232 to USB (to com port 5). Once I get into RSLinx and go to configure drivers, I select RS-232 DF1 Devices in the dropdown “Available Driver Types”. I proceed to click “Add New” and create a name for the RSLinx driver (SLC500_DF1). Once I hit okay, the “Configure RS-232 DF1 Devices” page pulls up. After changing my com port to 5, and selecting the SLC-CHO/micro/PanelView in the device tab, I click the “Auto Configure” button. It goes through and eventually pops up with “Failed to find the baud and parity! Check all cables and switch settings!”

    What am I missing here? Do I simplily have the incorrect cable??

    Any help would be greatly appreciated.

    Thank you,

  2. #2
    Administrator Shawn Tierney's Avatar
    Join Date
    Sep 2016
    Berkshires, MA
    Good morning Steven.

    This is a common issue and something I cover in my PLC Basics course.

    The first thing you need is a Null modem serial cable or adapter as both your PLC and PC are DTE devices. You can pin out your cable to see if it's a null modem or not by checking to see if pin 2 goes to pin 3 and vice versa.

    More info at Wikipedia:

    Next, most USB to Serial adapters do not have the required hardware for Auto-Configure in RSLinx to work. By all means try it when you have the correct cable, but if it fails assume your converter doesn't support auto-config and set all the settings manually.

    What are the default settings you ask? If you create a brand new 503 program in RSLogix and then look at the Communications Settings and you'll see what they are / what you should set RSLinx to.

    PS - My PLC Basics Second edition covers all this using the MicroLogix which is based on the SLC-500:

    It's on sale now, but if you miss the sale just drop me a message over at The Automation School and I'll send you a coupon,

    Hope this helps,

    Shawn Tierney,
    Instructor, The Automation School
    Looking for affordable automation training? If you are, check out my courses at!

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