Built-in Ethernet vs QJ71E71 Module

[valsidalv 0]

This is my company's first time using a Mitsubishi PLC and our partners/clients advised us against using the built-in Ethernet port on the Q03UDE CPU, saying that we should instead use a standalone QJ71E71 Ethernet module. The QJ71E71 costs 1.5x the CPU module so there are significant savings in using the built-in Ethernet. They cited reliability issues but can anyone here back up their claim? We use our PLCs as simple I/O blocks - a PC runs a program which communicates with the PLC and tells it what outputs to fire. There is no actual ladder logic on the PLC. The PC connects directly to the PLC. I wrote a small C# utility that blasts the QX40 and QY80 input/output cards on my stack with random values and reads them back to ensure correct data transfer. The QJ71E71 Ethernet module averages 10 ms for a read or write operation and the Q03UDE averages 3 or 4 ms (much quicker!). So, does anyone have a reason to use the QJ71E71 port instead of the CPU? Thanks

[Inntele 60]

I support the position of your client.On my memory, a built-in USB-port of CPU was easy killed with PC connection. This PLC has been mounted on a stand of demo-laboratory.The advice is to use an external isolated Ethernet-Hub.

[Crossbow 294]

I've heard of no such things. The main reason to use one over the other is the communication methods. One offers socket services and one does not. They had some good comparison documents on the functionality of each. I've used both, and never experienced a 'dead' module.

[valsidalv 0]

Thanks, that is what I expected, and wanted, to hear.

[dunc 8]

I agree with the above. never had any issues with either other than the stand alone Ethernet card needing a reboot every now and then on one particular PLC.