Bitwise Access

Used to read or control a specific bit of a tag (Tag_1).

• Usage: Tag_1.BIT(0) … Tag_1.BIT(63)
• Note: The data type of the source tag (Tag_1) must be large enough for the requested bit number (e.g., maximum .BIT(31) can be used for a 32-bit number).

WARNING:

When using bit addressing, all bits of the main tag (Tag_1) must be used either only for “Reading” or only for “Writing”.

The Risk: For example, if you change the 5th bit of a 32-bit variable read from the PLC via SCADA, the system writes the entire 32-bit value back to the PLC.
Data Loss: During this process, millisecond-level changes that occurred in other bits on the PLC side after the last read will be overwritten and lost.