Online Debugging Function - SMB MAT-LC-C Series User Manual

Contact setting/resetting
Contacts can be defined as set/reset contacts. A set contact is denoted by an "S" in the contact
symbol, it never overrides the TRUE value in the corresponding boolean variable, that is, if the
variable is set to TRUE, it will remain in the same state.
The reset contact is denoted by "R", it never overwrites the FALSE value in the corresponding
boolean variable, and if the variable has been set to FALSE, it will remain in that state.
When using the ladder diagram, the result of the contact switch can be used to control other
POUs. On the one hand, the coil can be used to output the result to a global variable, which can
be used elsewhere. It is also possible to insert possible calls directly in the Ladder diagram by
introducing a POU with EN input.
These POUs are complete normal operands, functions, programs or function blocks. They all
have an additional input designator EN. The EN input is a boolean variable, and a POU with an
EN input will only be calculated if the value of EN is TRUE.
6.3

Online debugging function

Sampling Tracking
Sampling tracing allows tracing the continuously changing value of a variable, relying on a
so-called trigger event, which is a rising or falling edge of a previously defined Boolean variable
(trigger variable). CODESYS allows tracking of 20 variables, each of which can track 500 values.
Debug
The debugging capabilities of CODESYS make errors easy to find. To debug, run the command
"Project" "Options" and select the activated option in the automatically popped up dialog for
creating options.
Breakpoint
A breakpoint is a place where program processing stops so that it can observe changes in the
value of a variable at a specific point in the program.
The breakpoint can be set in the editor, in the text editor the breakpoint is set at the line number,
in the continuous function diagram and the ladder diagram it is set at the network number, in the
CFC it is set at the POU, in the SFC It is set at the step, and the breakpoint cannot be set in the
instance of the function block diagram.
Single step
A single step is:
In the instruction list: Execute the program until the CAL LD and JMP commands are run.
In structured text: execute the next instruction.
In the function block diagram ladder diagram: Execute the next step network.
In SFC: Continue the current action until the next step begins.
Logic errors in the program can be checked by running it step by step.
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