LT3000 Series
From the [Project] menu, point to [System Settings] and click [I/O Driver]. On the [Int.Driver 1] tab, click [Standard I/O Settings].
The [Standard I/O Settings] dialog box appears. Define the [Retain Output] setting.
LT4000 Series
From the [Project] menu, point to [System Settings] and click [I/O Driver]. Specify the [Standard Output]. To retain output state, select [Save output value when logic stops].
When CH1 to CH4 are all set to "Standard", [Type] can be set to "Bit" or "Word".
When either Input or Output [Type] is set to "Integer" in the LT3000 Series, Special I/O cannot be selected in CH1 to CH4. When setting Special I/O, set all [Type] to "Bit". In the LT4000 Series, when the [Type] is set to [Integer] for output only, you can set special I/O for input.
Be careful when changing [Type] while I/O is already allocated. I/O mapping may be canceled, or errors may occur when saving or transferring.
31.5.3.3 Cautions When Changing Types