Polarity Reversal Relay Module are part of the Signature Series system.
They are intelligent analog addressable devices available in either plug-in (UIO) versions, or standard 1-gang mount versions. The GSA-CR/MCR Control Relay Module provides a Form “C” dry relay contact to control external appliances such as door closers, fans, dampers etc. This device does not provide supervision of the state of the relay contact. Instead, the on-board microprocessor ensures that the relay is in the proper ON/OFF state. Upon command from the loop controller, the GSA-CR/MCR relay activates the normally open (NO) or normally-closed (NC) contact.