Programmable logic controllers (PLCs) can be used to replace relays, timers, and counters. PLCs offer compact designs with flexible, programmable control and monitoring of devices. Operator interfaces or human machine interfaces (HMIs) feature touch-screen displays to control your PLCs and monitor and control automation and process systems. Programmable relays feature functionality such as control of relays, timers, counters, and time switching. Timers and counters are available as DIN rail or panel mount configurations. These instruments provide programmable counting/timing functionality for your process system. Signal conditioners accept many input and output signals and send the signal to the control device. Signal conditioners can accept temperature (thermocouple or RTD), AC or DC, potentiometer, bridge/strain, frequency, and many other types of input.