What Is CVM?
The CVM is CONTROLLER UNIT VOLTAGE MONITOR or FAULT MONITOR (FM) output from the Controller Unit, which is what the monitor looks at to see if the controller is in normal operation or in a fault state. When the TRUE (low) state is absent for more than the CVM Fault time (Section 9), the MMU2-16LE SmartMonitorĀ® will enter the fault mode, transfer the OUTPUT relay contacts to the Fault position, and display the CVM status screen. When the TRUE (low) state is absent for less than the CVM No-Fault time, the MMU2-16LE SmartMonitorĀ® will not transfer the OUTPUT relay contacts to the Fault position. The MMU2-16LE SmartMonitorĀ® will automatically reset the OUTPUT relay when the True (low) state is restored to the input. The MMU2-16LE SmartMonitorĀ® will remain in the fault mode for at least the time determined by the Minimum Flash programming. A CVM failure during the programmed Minimum Flash time or during an MMU Power Failure will not cause a fault condition.