We were setting up the DCS for a project. We had problems debugging the communication to the I/O.
Always with any system first thing is to get the I/O talking, scaled and displayed on the screen.
1) We didn't have the end stop module on the end of the stack.
2) The Siemens I/O communcation Manual doesn't have the Profibus Address dip switch configuration. Switches 1-8 set the I/O address. Switch 0?? set to 1 to get it to talk.
3) There are about 10 types of Analog Input modules. each one is addressed different. With a very long part number. Found a xxxxxxxabxxxxx module, when it was configured for xxxxxxxxacxxxxx.
When all three of these items were changed. The busfault light went out. And comm started up.
Time to go Home.
