2 Simatic HMI and One s7-300

Hello,

Is it possible to communicate two HMI on a single S7-300 PLC? If so what connection do i need to use can i just use the ethernet connection of the two hmi and the two ethernet ports of the siemens PLC?

My application will requires me to automate 2 different skids with just the same sequence but with different output devices the customer wants to have two seperate panels for the 2 skids and i thought why do not use just one PLC and just place all the I/O ,as it is not that many, in it and 2 HMI can use all the tags on that same plc so it will be much easier to create interlocking.

Thanks,
Joel

I would advise an industrial unmanaged switch in one of the panels and connect everything to that (circa £100 UK) so you can connect your laptop and any future equipment

Use Ethernet (Profinet) and just assign an IP address per piece of equipment

Cheers

Okay thanks

I was planning on using the S7-314c 2PN/DP cause i just have few i/o. Correct me if i'm wrong but i think using compact cpu is much cheaper than using standard cpu..

Thanks,
Joel

One word of caution which obviously depends on what control options are to be used on your screens but I have seen similar set ups where only one screen can be used at a time so that you don't end up with operators at different ends of a factory fighting each other for control when making selections on each screen.

yea but i already thought of that and i have a plan about that hehehehe thanks again

Joel201 said:

I was planning on using the S7-314c 2PN/DP cause i just have few i/o. Correct me if i'm wrong but i think using compact cpu is much cheaper than using standard cpu.

Click to expand...

Much cheaper still ... IM181-1 with ET200S IO. Has integral 3-port switch so you can possibly even save an external switch.

thanks for the advice. Right now we changed the design to 1plc 1 hmi but both plc need to communicate. I think using the Globaldata can achieved my goal is there any limit of tags that can be send and receive when using globaldata?