Mitsubishi fx comms problem

I am trying to set up an ethernet network between a laptop, a HMI(Mitsubishi E1101) and a mitsubishi FX3U plc with an ethernet module, I can download and monitor from PC to PLC ok, I can download from PC to HMI ok but there is no comms between PLC and HMI. I presume it must be a setting but cannot find out which! Any ideas or pointers would be appreciated.

i've never used that particular version of PLC but this shuold be the same old hut - you always make settings on HMI side so HMI can see particular port of the PLC.

in case you use ethernet, you have to specify IP addresses and subnet mask. ip address must be unique (you can't have PLC and HMI with same address) but the subnet mask must be the same (like 255.255.255.0)

another thing you may have to setup is station and network (again, first one is unique, second one is the same).

next thing is connection - how are they phisically connected together? most new computers support MDI/MDX (or auto crossover) but embeded products are not quite there yet. this means that if you happen to have fairly recent PC, you should be able to connect to either PLC or HMI by simply using any kind of ethernet cable (either straight which is most common, or - crossover).

but that same cable may not be good enough if you are trying to connect PLC with HMI (this is possible but cable must be crossover instead of straight).

if you only have straight cables, you must use hub or switch.