Comm between S7 400 and 555 - 1105


Thread Starter


We have two plcs. One is the S7 400 and the other is 555 - 1105. Both are siemens plcs. Is it possible to poll the I/O and memory locations
directly on the 555-1105 from the S7.If so how?

Tony R. Gunderman

Depending on the amount of data you are wanting to share, you may want to consider connecting the two systems using the DP-DP coupler
Siemens offers (part number 6ES7158-0AD00-0XA0). It sells for around $500. We are planning to use this transfer data between an S7-414 and
a 555-1106. It appears as a Profibus slave to both systems. Inputs on one are mapped to outputs on the other. The data shows up as I/O in
both systems and the configuration is pretty simple.

For larger amounts of data, options using FMS Profibus modules or Industrial Ethernet are probably better options.

Tony R. Gunderman
I have worked (and continue to work) with Siemen's S7-300 series PLCs and hardware. I am not familar with the 555-1105 you mention but does
it have the ability to connect through ProfiBus to your PLC? If so, then you can configure it to appear as I/O through ProfiBus and treat
it like an extension of the local I/O.

Gilles Allard

The 555 Profibus port is a master. You connot use it as a slave. As Mr Gunderman wrote, you can use a DP-DP coupler. Another solution would be to use a 2577 module (DP slave) offered by ControlTechnology


Alan Jenkins

CTI manufactures a 2577 Profibus DP Slave module for the 505 PLC's. The module is configured to enable reads of V, WX, C, or X; and writes of V and C's. Transfers of up to 110 words of input and 110 words of output per PLC scan are
For more information go to:

Alan Jenkins