Share your knowledge about "Profibus PA"

[fault40]

Hi,

Our Profibus system is DP and we used PA just recently for the process instruments like flowmeters,temperature,pressure transmitters or positioning valves but knew very little about allocating I/O's for these instruments. Is there any specific numbers of I/O's needed and how many of them to allocate for each Instru?(PLC used: Siemens TI and S7-400)

Your input on this querry will be valued!

fault40

 

[dchartier]

Hello Fault40;
We did a project 2 years ago using TI555 PLCs and Siemens Sitrans flowmeters. On the DP side, we could configure the DP/PA link (IM157) as a Profibus-DP slave in ComProfibus; but we could not see the PA side . We needed to generate a PA profile ( in Simatic PDM) for every device on the PA side. Once this setup was integrated in the DP config, we could merge the ComProfibus file in TiSoft; we were then told how many words we needed to reserve for the PA devices.
Simatic PDM can be integrated in Step & (especially useful if programming S7 CPUs); it can be used for Profibus Pa devices or HART communications. The file can be exported to Tisoft or Step5. Please look at the Siemens support webpages (start at

http://www.ad.siemens.de,

then Support, service and support...) for more info and manuals.
Hope this helps,
Daniel Chartier