Communicate between AC800M and Siemens CP 1542-5
Hi!
I'm trying to setup a communication between an AC800M Ci854 and a Siemens CP 1542-5. In the Siemens there is setup 8 bytes for outputs and 8 bytes for inputs. QB100-107 and IB200-207. I have made a standard conversion of the GSD-file but which one of the hardwaretypes should I use? The C 1542 node of course but on the lower level. 8 bytes input unit or 8 of 1 byte input unit? I have no success what ever. Any suggestions? In the webbrowser we can see the node.
Answers
Hi,
I'm not quite sure about CP1542-5, I made a Profibus communication with Siprotec relays. What I know from there is the following:
- CI854 must be master, so CP1542-5 have to be configured for slave
- From AC800M with CI854 should request exact number of input and output bytes, as they are defined in slave device (mapping), in your case CI1542-5. Otherwise the communication is not working. You have to make some tests, until that happen
- If you are sure CI1542-5 is defined to exchange 8 bytes for outputs and 8 bytes for inputs, you have to see what kind of information is in these bytes (only binary signals or also some measurements - int?) From that you have to decide how to read this from CI854 as there is a limitation in total bytes you can exchange.
For example - 8 bytes input can be read as 1x8 bytes, or 4 words, or 2x4 bytes or...
All these depends what kind of data are configured in these bytes.
Pay attention - if in siemens device there is a handshake byte, you have to use Wordsk consistent
Again, first try to establish communication between CI854 and your slave device by using of exact number of bytes as required (doesn't matter using 2x4 bytes or 1x8bytes or 4 words). Then, by suitable combining of the right format will adjust to receive what you need as per slave's mapping
In case you provide more information for the mapping of your CP 1542-5 slave configuration, I can try to advise about the read/write format
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