However, it may be used on any boolean within the program. Note 1 – The OTL instruction was initially used to set the status of miscellaneous outputs landed on the PLC.Boolean – The OTL may only set TRUE or 1 or HIGH.The OTL instruction will work with the following data types within the RSLogix 500 environment: The bit which was energized by the OTL instruction will remain energized after the release of the start button or any other condition tied to the input of the OTL.

Outcome: The OTL instruction will energize the output of the PLC which will allow the motor tied to the starter to run.

The output (O:0/0) remains HIGH when the XIC is released.

The OTL instruction energizes the output (O:0/0) while the XIC is TRUE.

A normally open push button (“System Start”) is connected to Input 0 (I:0/0 of the PLC).

A motor contactor is connected to Output 0 (O:o/o of the PLC).

A Micrologix 1100 Allen Bradley PLC is used to control a process.

Here’s a real-world scenario of an OTL instruction: The rung in which this instruction is used will not be monitored until a separate condition unlatches the output through the use of an OTU instruction. In other words, once the conditions are met for the output to be energized, an output latch instruction will set the output to HIGH until it is unlatched. The latch portion comes into play when the output must be energized for an extended duration. Similarly, energizing a valve will toggle the state and open or close the valve depending on the initial state.

In other words, energizing a motor coil may start the motor. The purpose of energizing an output is to toggle between the two states of the device tied to this output. A few examples of such devices include motor starters, relays, valves, solenoids and lights. In PLC programming, an output is tied to an electrical device that most often performs a mechanical action. That being said, the most common pairing with an OTL is an OTU (Output Unlatch). In order to make that happen, you can leverage other instructions which accomplish exactly that. Unlike the OTE Instruction, the OTL will never turn the bit LOW. This instruction is found on the right side of a ladder logic rung and will switch a bit to a HIGH state once it executes. It’s a basic instruction which is powerful but can cause programmers a lot of grief if used improperly or too frequently. The OTL, also known as the Output Latch, instruction will force a single bit of logic into a high state if all the conditions leading to it are true.

Tof plc ladder