I have a S7-300 with the following profibus nodes:

4xET200s

32xled displays (http://www.gs-gmbh.net/products/led-displays-and-panel-mount-display-small-led-displays.html)

2xIM153-2 each with two FDC157

32xLR560 profibus PA radars.

All profibus rules are followed and repeaters are placed where they should be etc.

I load my hardware configuration and all slaves are available.

The led displays have 4 digits and I send one byte per digit in ASCII.

In my FBs I use QBx addressing to send the data to the displays.

All displays work well except from the last 4. i use a VAT table to write data to the QB of the last four displays but it doesnt work. Then only for the four displays I used PQBx addressing and it worked.

So Only for the last 4 nodes of the profibus QBx addressing does not work, but PQBx does. Isnt that strange?

Another thing i am not sure about is that by downloading only the above mentioned hardware configuration 43kb of Mmc memory are consumed. Why is it so much? Are the gsd files downloaded to the MMC? Is there a way to save memory from that?

Regards