Hadi.B

No they were not prefabricated. They were CAT6e I think. Actually, all cables (both LAPP and Beckhoff) and connectors we were using were good and expensive. Also the connections we checked several time by multimeter. But they did not work properly and finally, prefabricated cables worked. I exactly do not know what happened there. Maybe the impedance changes at the connecting point.

I want to appreciate all suggestions made to solve the issue we had. Beckhoff representative was here to check our system with Beckhoff PLC and he saw the same issues we had.  We did a few tests on the EtherCAT communication. In all tests, the connections were good and correct and they were checked several times. Test 1: PLC and two IO with a normal 4 wire cable for EtherCAT network         Result: IO could not connect at all to the EtherCAT network.    Test2: PLC  and two IO with the current cable that we have (the brand is Lapp) for the EtherCAT network         Result: Around 10 frame loss in a few hundred thousand frames (Normally frame loss can be neglected by the master) plus a complete disconnection normally around 4 to 5 minutes   Test 3: We did test 2 with another cable (same brand and same model).         Result: same as test 2   Test 3: PLC and four IOs and cables from Beckhoff for the EtherCAT network:       Result: a few frame losses (which is neglectable) in one million frames and no disconnection.   Test 4: In Test 3, all frame losses happened only in one node so we changed its cable. And now, after sending 10 million frames there is not even one frame loss, this is great.   I have ordered prefabricated cables from Beckhoff in Germany that I think can solve our issue.  The big lesson we learned after weeks of working on this and engaging Omron and Beckhoff's supports in it, is that the cables in communication are very important. Checking the cable connection only by multimeter will not be enough (We had a very good cable with good shielding and also expensive EtherCAT connectors from Beckhoff) and the best always is using prefabricated cables. 

The thing is that I have the issue while I am connecting with a plc to IO on my desk. When I saw this issue in the machine I made a small set up with only two IO and one PLC. Nothing more, No switch and no middle device. Still I have same issue. I have ordered some prefabricated cables to just test them. 

There is no extra device in the network. The plc is connected directly to node 1 and node 1 to node 2 and so on.

Yes I did. Different etherCAT cables and different Power cables. 

Hi, I have a problem with Omron PLC and Beckhoff IO. The IO just disconnects in a few minutes and comes back! I received different errors: Link off error, Illegal slave disconnection, process data reception timeout. When I also check "Display Diagnosis/Statistics information" I see errors on all ports A and B of all nodes.  I have called and talked to both Beckhoff and Omron.  I have two NX1 and one NJ101 to test. And I have three EP2318-0001. I have the same problem with all the PLCs and EP boxes. It does not matter if I have one, two, or three nodes. I have tried different revisions of the EP2xxx from the XML file, different settings for the slave, different task periods, and the error still is persisting.

Hi, Correct. Thanks.

Hi, I wanted to run an SMC linear actuator and found this error in axis settings: No device is assigned to the required item. More strange is that I checked one of my old programs in which I ran a Fastech motor (with Ezi driver) by Omron Nj501 series. Everything is OK and the system works. But, If I change "output device 1" in "axis basic settings" to "<not Assigned>" then re-select again my Ezi driver it does not work and I get the same error message. I checked everything. There is no change in the axis settings.