BreadGuyJeff (Customer) asked a question.

Edited March 12, 2025 at 7:56 PM
Difficulty connecting programming computer via Ethernet LAN with P1-550

I am using the P1-550 and a P1-RX remote IO unit and I am having a great deal of difficulty connecting my programming laptop to the PLC through the Ethernet port. It does work sometimes but it is very slow, like the PLC isn't discovered in the Choose CPU tab until after several refreshes and once I connect a the Clock Seconds register only updates about once every five or ten seconds. The computer is directly connected to the PLC Ethernet port with nothing else on the network and I have tried multiple Ethernet cables.

 

This is my first time using the remote IO and I am wondering if that slows down the Ethernet port? I use another P1-550 in another application and it's connection is lightning fast. Also I pinged the IP from my windows cmd prompt and it was less than 1 ms. And roundtrip is reported as 0 ms.

  • 4 answers
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  • BreadGuyJeff (Customer)

    Bad hardware, but my fault!

     

    I found my RJ45 connector I crimped on had 2 pins that did not crimp fully(strange how this happened as I used a quality Klein crimping tool but I will inspect this more carefully in the future). One of these pins caused the female port on the PLC to have a pin get bent down and stuck. It is strange it worked at all but basically when pinging it I would get fast responses but about every third or fourth packet was dropped.

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  • ADC Community_02 (Automationdirect.com)

    Since you have another CPU that works without issue. Have you tried changing out the CPU with the connection issue with a spare CPU? Could be a bad ethernet port on that unit.

     

    What firmware is running on both the CPU and RX? Are they at the latest revisions?

     

    Using the remote i/o port will not affect your ethernet connection speed.

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  • BreadGuyJeff (Customer)

    P1-550 has 1.3.0.4

    P1-RX has 1.22.0.0

     

    I will try to swap the CPU with the other one I have on Friday but it is on a running machine and I can't do it till then. I also ordered another new CPU that should arrive Friday.

     

    I need to add that upon further pings from my computer it seems like a fluke that the first time I did it all 4 came back less than 0ms. I repeated this several more times and generally out of 4 packets sent 1 of them is timing out.

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    • PouchesInc (Customer)

      Sounds like either bad hardware or misconfigured network, but since you are direct connected between the laptop and PLC CPU that takes the network mostly out of the equation.

       

      Is the laptop set for static IP and on the same subnet as the PLC IP is?

      Is the PLC set for static IP and not trying to also get a DHCP address?

       

      What is the PLC IP and subnet?

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  • BreadGuyJeff (Customer)

    Bad hardware, but my fault!

     

    I found my RJ45 connector I crimped on had 2 pins that did not crimp fully(strange how this happened as I used a quality Klein crimping tool but I will inspect this more carefully in the future). One of these pins caused the female port on the PLC to have a pin get bent down and stuck. It is strange it worked at all but basically when pinging it I would get fast responses but about every third or fourth packet was dropped.

    Expand Post
    Selected as Best

 

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