The PLC can be specified to perform a limited number of scans on the program (from 1 scan to 65535 scans). By specifying the number of scans the PLC runs, the change of program process variables can be monitored. At the first scan, the SM0.1 value is 1. 1. Execute a single scan “single scan” to change the PLC from STOP to RUN, execute a single scan, and then switch back to STOP, so the status information related to the first time will not disappear. The operation steps are as follows: (1) The PLC must be in STOP mode. If it is not in STOP mode, switch the PLC to stop mode. (2) Use the menu “Debug” → “First Scan”. 2. Perform multiple scanning steps as follows: (1) PLC must be in STOP mode. If in STOP mode, switch the PLC to stop mode. (2) Use the menu “Debug” → “Multiple Scans” → the “Execute Scan” dialog box appears. (3) Enter the desired number of scans and click OK.