Chapter 3 Downloading and Monitoring the Program 3.3 Monitoring and Debugging the Program 3.3.1 Monitoring the Program When the program is executed, users can monitor the program to understand the current logical control state, or modify the values in some devices to test the system. The operation of the program monitoring is as follows. Monitoring the program Open the Prog_Main window, and click . Not only the logic program, but also the information related to the devices is monitored. (If the data type is a Boolean value, the state of the device is represented by green (ON) or white (OFF).
If the data type is not a Boolean value, the value in the device is shown.) If users want to alter the value in the device, they can click the right mouse button. Tank_B1F_LSW is the device which is modified here. Please notice that the device corresponds to an actual I/O device. Setting the device to ON or OFF is meaningless because the actual I/O value covers the setting value immediately. To alter the value in the device, users need to force the device ON or OFF. The value in the device is altered, and a lock symbol indicating that the device is forced ON appears. 3-9