PLC online

Hi all,

What are the necessary steps to see the input and output cards flashing on the PLC to see if a simple program works.
I have created a new project in step 7 with a function block containing a simple ladder program, configured the hardware and downloaded to PLC. The PLC is running online fine, and able to run the debugging tools. How do I go about seeing a simple (i.e. two switch AND gate) work on the actual PLC and force the inputs on and off using step 7 software.

Thanks

Tom

Hello wglespaul;

The easiest way to see your logic work in Step7 is to use the monitoring functions available in the LAD/STL/FBD editor. Open the block (OB, FC or FB) you want to look at, make sure you are connected to the PLC, then click on the "glasses" icon on the icon bar. This will show you active and inactve inputs/outputs directly on your logic (especially true in LAD or FBD).
If your logic gets more complex, and you have to monitor items in different blocks, then you can use a VAT table (Blocks, insert block, Variable table) where you can setup a number of addresses to monitor. Again use the "glasses" icon to go online.
One more way, if you wish to see the activation staus of inputs and outputs from their rack/slot addresses, is to open the HConfig editor, right-click on a module you want to monitor, and select monitoring.
Hope this helps,
Daniel Chartier