Glossary · Electrical engineering and control panels
Output
Also known as: Output channel
German: Ausgang
In industrial control, an output is a controller or device channel that sends a signal to the field or to another system to act on the process, such as switching a valve, setting a speed or lighting an indicator.
- Control panels
In one sentence
An output is a channel that sends a signal from a controller or device to act on the process, such as switching a valve.
Example
Output Q4.2 of the PLC switches the indicator light that signals "machine ready".
How it applies
- Engineering: For every output, define the connected device, the signal type and the state it takes when the controller stops, loses communication or detects a fault. These states must be consistent with the machine's safe state concept.
- Commissioning: Output tests move equipment. Test outputs only with the hazard area cleared and with the right people informed.
- Documentation: I/O lists name each output with address, tag, device and fail state. In German, "Ausgang" also means the exit of a room or building; context and terminology databases should keep the electrical meaning separate.
Output vs. output value
The output is the physical channel. The output value is the data written to it by the program. Forcing changes the output regardless of the program's value, which should be clearly indicated.