Breakpoints

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By breakpoints you can interrupt the process of the PLC-program at any position. The process of the simulation is stopped then as well.

  Setting of a breakpoint in STL

  Setting of a breakpoint in FBD/LAD

After the program is stopped the CPU window is displayed and the LED at the bottom left becomes yellow. On the CPU window there are four possibilities to continue the process of the program:

 

1.) Continue: Here the process of the program is taken up normally again until the next breakpoint is reached. Instead of the button you can also use .

 

2.) 1 Network: Here a network is processed and stopped after the last line has been processed. This is a little irritating in STL because one expect that the process is continued until the beginning of the next network. But a FBD- or LAD-network can only be displayed usefully in the mode monitoring after all instructions are processed. If the network contains a block call the process will be stopped prematurely so that you have the possibility to follow the process in the called block by ‘Trace’ (see below).

 

3.) 1 Step: Here exactly one program line is processed. If the program line is a block call this block will be processed completely but not displayed. This button is not very useful in FBD/LAD.

 

4.) Trace: Even here the program is processed line by line, but at calling blocks the process is also done in the called block line by line.

 

If you click the program will be processed until the end of the current scan and the simulation will be stopped. If a further breakpoint appears while processing that one will be ignored.

 

If the end of the scan is reached during the process of the program that is done step by step the machine simulation will be processed once, you recognize this by the marching on of the simulation time in the main window at the bottom left and by the short flashing of the green LED.

 

You delete a breakpoint in the same way as you have set it:

Click right and select the menu item ‘Breakpoint’.

 

You can also specify conditions for the breakpoint: for this select ‘Edit Breakpoint’ after clicking right.

 

If you want to transfer a block into the PLC during the process that is done step by step (a transfer is also necessary for switching on/off of the monitoring mode) you will be told that this is not possible at the moment but that the block will be transfered automatically at the end of the scan.

 

See also:

Speed-Trigger

Monitoring

 

Because of compatibility reasons to older versions there is also another form of the breakpoint.