S5 TO S7 CONVERSION using existing S5 i/o

Has anyone run into problems using existing S5 i/o ( specifically the et200u) interface modules with the S7 cpu. I have done this already using the S7 315-2DP and the 6ES5 318-8MB12 IM. I am now trying to use the S7 317-2DP and the 6ES5 318-8MB11 and they absolutely refuse to talk to one another. Any ideas?

Hello ipsco;

Information from Siemens on their ET200-U.pdf manual:



The 6ES5 318-8MB11 cannot be used for Profibus-DP comms; you must use a 6ES5 318-8MB12, as in your previous project.
Hope this helps,
Daniel Chartier

Hello Daniel.

Do you know what is the big difference between the SINEC L2-DP and Profibus DP (../part 3) specifications ?

I thought that "SINEC L2" was an old Siemens name for "Profibus".

Hello Jesper;

Somehow I don't have access to Siemens' site at the moment, so I have to rely on memory and files I have saved over the years. Basically, I would agrre with the following statement:

[quote from the Fieldbus Unreferenced List]
Sinec L2 (also called L2/DP) was partially based on existing Profibus technology (FDL) which is the lower layer (OSI Layer 2) only. The L2 specification described how to use FDL in order to create a remote I/O system with it. Actually L2 is quite simple, the specification is only 15 pages A4. The L2 protocol gradually evolved into the first version of Profibus/DP, after Siemens started cooperating with the Profibus User's Group (PNO). As of 1993, with the release of Profibus/DP, the L2 protocol quickly disappeared.

Which is why on the 318-8MB12 yoou have a dipswith that will transfer you to "DP-Siemens" (S5 Sinec L2) to "DP-Norm" (Profibus-DP).

Extracted from the ET200-U manual:



Hope this helps,
Daniel Chartier

Thanks Daniel.

I did not know that SINEC L2 DP was an initial implementation Siemens Profibus DP, and that it is incompatible with Profibus DP.

I thought that SINEC-L2 simply meant "Profibus" and thus SINEC L2-DP was the same as the current "Profibus DP".

Daniel, you are good. That is the reason there were multiple versions of the 95U. There was a B version that supported L2, E was a profibus master and D was a profibus slave. It was a bummer that the L2 version and the slave version had different protcols built in. When customers wanted to upgrade from L2 to profibus, they were stuck. There were driver issues for the HMI guys also.