The PPCL Editor provides several ways to help troubleshoot your programs.

Comment out or go around lines of code

You can comment out or go around (disable) one or more lines of code in your PPCL program, run it again, and then use the results to help debug the code.

Trace Bits

When you modify PPCL code, you should first clear trace bits from the previous PPCL code to ensure that the program runs properly. Clearing trace bits helps you follow the flow of PPCL execution. With trace bits cleared and PPCL code displayed, you can determine if certain statements are being executed or bypassed. This is a useful tool for debugging PPCL code.

Inline Notifications

Syntax, fault, or unresolved errors in a program will be indicated with Inline Notifications. Inline notifications will appear above the PPCL Editor controls.


The SAVE ERROR bar handles invalid PPCL, such as duplicate lines, lines out of range (greater than 32767 or less than 0), lines without a line number, and other types of improper line syntax. Lines with improper syntax will be automatically commented out by the compiler and placed in the SAVE ERROR bar at the top of the PPCL editor work area after saving instead of discarding them without a warning. This allows you to see invalid program lines that you want to copy and paste back into the program after editing them so they are valid. You can also delete the lines altogether so they are not included in the program.

Correct or discard invalid lines and delete the SAVE ERROR bar, or the SAVE ERROR bar will populate within itself on the next save.


Any unknown PPCL commands will be added with an UNKNOWN (...) marker and ignored by the compiler upon saving a program. Correct or discard unknown commands and save the program again.

Line status indicators

Line status indicators appear at the beginning of each line of the program and provide diagnostic information about the line of code. Hover over the line status indicator to see the full status indicator. Multiple line status indicators can display for the same line.

Cycle time

Program cycle time metrics for different PPCL programs, such as Average cycle time(last 10 cycles) in ms, Highest cycle time in ms, and Lowest cycle time in ms, can be seen by clicking on the respective program object in My Folder > Programs. These metrics can be mapped to virtual points and trended over time.