An electronic counter is a device that stores (and often displays) the number of times a particular event or process has occurred. This can be in relationship to individual, intermittent signals from a sensor, switch or similar. In motion control systems the signal is often provided by a feedback device, such as an encoder or linear scale.

The counters can be used as:

• Position indicators for incremental and absolute SSI encoders and linear scales
• For batch counting
• As tachometers or frequency meters
• To monitor speed and/or motion

A counter can provide low-level control functions such as switching an output when a pre-set position has been reached. In the main they are used to indicate a value derived from the feedback device (similar to a digital read-out or DRO).