Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 104)

Preface MicroLogix 1000 Programmable Controllers User Manual
6–6
Using OTL
When you assign an address to the OTL instruction that corresponds to the address
of a physical output, the output device wired to this screw terminal is energized
when the bit is set (turned on or enabled).
When rung conditions become false (after being true), the bit remains set and the
corresponding output device remains energized.
When enabled, the latch instruction tells the controller to turn on the addressed bit.
Thereafter, the bit remains on, regardless of the rung condition, until the bit is turned
off (typically by a OTU instruction in another rung).
Using OTU
When you assign an address to the OTU instruction that corresponds to the address
of a physical output, the output device wired to this screw terminal is de-energized
when the bit is cleared (turned off or disabled).
The unlatch instruction tells the controller to turn off the addressed bit. Thereafter,
the bit remains off, regardless of the rung condition, until it is turned on (typically
by a OTL instruction in another rung).