S7-400 DP-Slave Module

[ciwa]

Hi All.. How to connect expansion rack to central rack of S7-400 using profibus. Is there any S7-400 DP-Slave module? Regards, Ciwa

[JesperMP]

Hi ciwa. edit: I deleted my previous entry. I misunderstood what you are after. This is the correct answer: There is no DP slave adapter module for an S7-400 rack. Strange as it seems, if you want to operate multiple racks of S7-400, you have to use IM SEND and IM RECIEVE pairs. As S7-400 i/o is quite expensive, you could consider ET200M or ET200S in stead of S7-400 racks. Edited April 7, 2008 by JesperMP

[jacekd]

What do you mean by an expansion rack ? Is it a S7-400 ER or UR rack ? If so you need to use a pair of IM460/IM461 modules. I've never heard of kind a "DP slave" module for S7-400 (something similar to ET200M). It's also posible to use a CR/UR rack with a S7 CPU configured as a DP slave. However this option might be "over engineered" in your case... If you have to use Profibus DP then maybe ET200 or other remote IO system is the way to go for you ?

[Mike Dyble]

I havnt got the manuals in front of me, but I am fairly sure you can make the S7-400 2nd port a DP slave, which then maps into S7-400 which is the master. But this would mean having two CPU's, and they would both be 'Central racks' Otherwise I think you can have them both as masters and use the Send and Recv FB's to pass data between them. Have a look on the Siemens web site, as I am have seen worked examples of what you need there, but you still need two CPU's There is no module that I am aware of that allows you to use Profibus in place of the traditional rack to rack cable and IM module Mike Edited April 7, 2008 by Mike Dyble

[ciwa]

I agree with you jesper, but my client still want to use S7-400 I/O as remote I/O, there are 7 remote I/O. Using old conventional multi core cables. I really don't know what this mean? Really expensive project..!! regards, ciwa

[Mike Dyble]

Another question. How far apart will the racks be?

[JesperMP]

I really do find such a layout both cumbersome, expensive, and outdated. But if the customer already use this method, then you should stay with it. And as he insists, then there is really no need to discuss any longer.You need to look into the S7-400 manuals to understand how multiple S7-400 racks are setup with IM Send and Recieve modules. Notice that both modules and cables are dependant on the distance !

[ciwa]

Less than 5 m. I will use IM 460-0 and IM 461-0. Thanks for advance. Ciwa