Hi,

I`m thinking using Stahl ET-208, see attached datasheet.
We need to use existing cabling so I was thinking using a MPI interface. According to the datahseet from Stahl support the panel MPI on RS485 / RS-422.

[snip]

Will I configure the interface on the Stahl side (in SPSpluswin), where you define the tag list with read and write bits and word and then will the panel write to the PLC?

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Split from MPI communication (Stahl panel).

Please see attached screenshots, these looks straight forward for me?

The next questions is, I need to connect two ET-208 panels to these MPI port,
I know on other project we have used a Helmholz Multiplexer 700-750,

Is these a good option here also or do I have alternative solutions?

Is need a multiplexer for be allow to install two panels to the same MPI port?

Hello,

[snip]

Don't know if multiplexer is needed, if you want you can attach next Panel to MPI in daisy-chain system (RS-485) with PB connector and also cable, each of panel need to have unique MPI address other than PLC and PG (standard 0). In Panel documentation you can find relevant infos what you need set in case of needed network.

I have figured out more about these now. You need to use a Stahl MPI adapter, then can the ET208 communicate with the Siemens 400 PLC.

The only questions I have now is support Siemens 414-3 we connect two MPI devices (two ET-208 operator panels) or must we use a multiplexer or something?

I will give you full information.

I only have to pair to use from the cabinet to the panel in the field.

Project 1:
I need to connect one Stahl ET-208 to the Siemens 400 MPI port.
Stahl informed me I needed these MPI adapter to be able to communicate on MPI.

Project 2:
I need to connect two Stahl ET-208 panels to the same 400 MPI port.
I only have to pair to use for each panel.

Please see attached ET-208 datasheet, the grey box you see on the MPI communication is the MPI adapter according to Stahl.


So I have two questions:

[snip]

2. What must I do, to be able to connect wo ET-208 panels to the same MPI port.

Hello,

probably clear now, that Panel hasn't MPI natively but use RK512 so your mentioned adapter must be used in this case. Second question you must send to Stahl, but I see this probably (only my opinion) that you need better second adapter connected to second panel. I see RS-422 on adapter but probably can't imagine clear multiplexing of communication here. Only my opinion. For sure contact with this (using multiplexing/second adapter) Stahl. I see probably one adapter (some kind of gateway) as unique MPI address occupation, so probably I see second adapter needed. Nevermind, this info give you Stahl, what to do.

Thank you.

[snip]

Project 2:
Where I have two panels, if the MPI adapter is working (ref. project 1), must I use a third component who can stand in between the MPI port on the PLC and the two MPI adapters

agree?

Hello,

[snip]

2. you must ask Stahl (as I've mentioned before).

Solution is found:

I will use SSW7-RK512 on each panel (MPI adapter) and then a FLEXtra® twinRepeater, 700-972-2AA02 to be able to connect two MPI signal into the same MPI port.

Both product produce by Helmholz.