Message S7 To Slc 5/05

Hi All

I have been asked to set up a message block in a S7 300 plc to a
Slc 5/05 via e-net.I have no problem on the Ab side but could any
help me out on the S7 side as I have not worked a lot on this.
I do not have the card for the S7 yet but I would like to be a head
and have a plan in place before it comes.

Thanks for your time

Donnchadh k.

Bad news for you.

Although S7 and SLC both communicate using Ethernet, the application protocol are totally different and incompatible. You will not be able to send a message on Ethernet from one to the other.

If I had to link a SLC and and S7 I would choose Profibus DP, as a protocol they both have in common. SLC-500 would use a Profibus DP module from SST.

There may be ways to use software intermediaries to do this, like an OPC mirror, but it's not going to be simple.

Hi Ken

Did not think it was going to be easy looks like proifbus is the way
from here.

Thanks for taking the time to reply

Donnchadh K

The profibus module for the SLC is definitely an option.

Also, if serial is viable (no need for high speed comm's), you may want to look into plugging a serial RS232 to Ethernet converter into you PC or TS adapter and then taking you ethernet port on the SLC and the newly installed converter that's now on your Siemens PC adapter back to a hub/switch (I would reccomend a switch for full duplex operation). Sixnet makes the RS232 to Ethernet converter and they make a nice industrial switch too.

upon a second reading of you original post, I noticed that your goal was to establish a "message block" , by "message block" I am assuming that you mean a data sharing connection between processors. If you did the 232 to ethernet conversion like I outlined above, I believe that you could use the msg instruction in the SLC 5/05 to accomplish your messaging needs with the setup I described. The msg instruction in the SLC 5/05 can read and write. Read up on the msg instruction (or call rockwell) and see if it can "write" in a language that the S7 will understand, If it won't then see if the S7 can "read" (go and get) data from its channel where you have the PC adapter/232-Ethernet converter, If the s7 can "read" then do a msg read in the SLC and do a "read" in the S7. This way you are only limited by the baud rate at the converter/PC adapter.