Chapter 18 Testing and Debugging Tools 18.1.3 Changing the States of the X Devices in the Online Mode In the online mode, users can change the states of the contacts in the program editing window. Users may not be allowed to change the states of the X devices in some PLCs in the online modes owing to the design of these PLCs. If users want to change the state of an X device, an error message will appear. Please refer to the manual for the model selected for more information. If an X device needs to be operated when the program is tested, users can click on the toolbar to enable the function of setting the X device.
However, the state of the X device will not be updated after the function is enabled. After the online monitoring function is disabled, the function of setting the X device will not be disabled automatically. As a result, be sure to disable the function of setting the X device before the online monitoring function is disabled lest the state of the X device should not be updated during the operation of the PLC. Before the state of a contact is changed, users have to make sure that the operation performed does not affect the operation of the system, or cause damage to the system or the staff. 18-7