Profibus Communiction with CVM 144 Power meter

(d) Diskette with PROFIBUS driver (GSD file).

Together with the metering unit, also the *.GSD driver is factory supplied. This driver is required to complete the Master PROFIBUS program. In case that you do not have this driver, you can also download this from this internet web-site: www.circutor.es.

Once you have the gsd file (the extension could be gsd, gse, gsf, gsg... depending on the language used to write it) you must insert it in the Profibus catalog of the master. For a Siemens master, open the HWConfig editor, close all projects that are open (just an empty screen) use the menu Tools-->Insert gsd file to insert the new file. Then open the project you are working in and you will find the new slave in the Profibus catalog (click on the line that represents the Profibus network.
The attachment shows the data available in the slave throughthe gsd file; you must select a maximum of 4 "modules" with a maximum of 244 bytes in total, so design your exchanges with that in mind.
For example, if you choose the last module, Cos phi (Power Factor) you will get 12 bytes IN; 3 phases, 4 bytes each (probably REAL values, in floating-point format). Simply read each value based on the start address given by the configuration of the module.
No functions are necessary (just Move PIW xxx to a DBx.DBDxxx address if you need to process it further), unless you want to read the complete 52 bytes (in a single read operation)from module 1 for example. Then you would need to use SFC15/SFC 14.

Take a few minutes to study the following documents to make things clearer:
- a sample procedure to setup a non-Siemens Profibus-DP slave with a S7 DP-master:

How to configure an Anybus PROFIBUS Slave module

- an application notre detailing the use of SFC 14/15 for consistent data exchanges:

Consistent Data - Siemens Industry Online Support

Hope this helps,
Daniel Chartier