When monitoring PLC code (perhaps during fault diagnostics), there may be a need to view several individual lines of PLC code from different parts on the program. Normally this would mean jumping about in the ladder code but you would not be able to see these lines of code at the same time.
Here we explain a feature called “Entry Ladder Monitor” in the GX Developer PLC programming software that provides the required functionality described above.
To use the Entry Ladder Monitor feature you first need to have your PLC program displayed on screen in ladder view. Go to the Online menu and then select Monitor, and finally Entry Ladder Monitor. This opens a blank Entry Ladder Monitor window.
At this point it is useful (but not essential), to split the screen so that the ladder program window and the Entry Ladder Monitor window can be seen at the same time, as shown below.
You can now “cut and paste” lines of code from the normal ladder window to the Entry Ladder Monitor window. The cursor needs to be placed on the far left-hand side of the normal ladder window, as shown above, for the line of code to be copied.
You then place the cursor on the far left-hand side of the Entry Ladder Monitor window and paste the line of code. This can be repeated for as many times as you need to get the required lines of code into the Entry Ladder Monitor window. See example below:
Once the Entry Ladder Monitor window contains the lines of code required, monitoring can be turned on.
For further information see GX Developer help and manuals.