This document discusses different types of telemetry used in instrumentation systems, including frequency, position, and multiplexing telemetry. Frequency telemetry represents measured values as an alternating current or voltage of varying frequency. Position telemetry relates the signal to the measurement to allow the receiving instrument to display displacement. Multiplexing telemetry allows transmitting multiple measurements over a single channel using either time division or frequency division methods to share the channel. This conserves resources compared to using separate wires for each measurement.