Hi!
I have recentlyestablished Profibus DP connection between S7 and ATLAS Copco, in Step7, not in PCS7. I can explain procedure shortly, only for Step7.

1. Electronicon ComBox is a Gateway between Profibus and CANBUS. Profibus master communicates with this ComBox; Compressor (one or more of them!) then communicate with a ComBox through local CAN bus.

2. "Profibus side" of Combox must be properly programmed. In our country, it can be done only through authorised personal (from Atlas Copco). The proper buffer structure (see chpt. 4.2, page 8 of manual) must be programmed in. PB address of ComBox can be set on Bottom address switches on the device (see photo on page 5, chpt. 2.2).

3. HW configuration: where did you get a GSD file? I could not find it on the net, therefore I had tocreate it bymyself, according to example in manual (chpt. 6, page 54)! Anyhow, in HW configuration, you have to programm the same "buffer", as it was earlier programmed on ComBox.

4. Understanding of communication principle: each question or answer is allways 8 bytes long (= 1 data record). Structure of data record:
Byte 0: Header
Byte 1: Node address (Than is a CAN addres of connected compressor on "CAN" side of gateway!)
Bytes 2 and 3: so called "profibus parameter"; this is the number of parameter (of the compressor!), which is to be read or written to; detailed explanation of parameter numbers and their meaning is in manual!

For example: in my case, actual compressor pressure could be seen on Analogue input 1. According to description, this is a profibus parameter Nr.0 (see pages 21, 22).

Bytes 5 to 7 are then dependent on values in first 4 bytes; you have to study this from parameter to parameter....

5. Byte 0, Header: header is explained in chpt. 4.3, page 9,.....For proper understanding of communication mechanismtry to "dig" through example(s) in chptr. 5, page 51 ......

6. Some interesting parameter numbers, which I used in my application:

- actual compressor pressure: parameter 0 (An. In.1, page 21)
- actual oil temperature: parameter 4 (An. In. 5, page 21)
- actual ambient temperature: parameter 6 (An.In.7, page 21)
- actual compressor status: parameters 400, 0401 (page 13)
- actual speed of motor (if you have a compressor with VSD): parameter 801 (page 30)

.....

7. Programming in Step7: I could not find any dedicated FB or FC for this communication, it has to be written separately