A retentive timer in a Mitsubishi PLC maintains its timing value even when power is lost. By retaining data to a non-volatile memory chip on the PLC’s circuit board, the value will not be lost during a temporary or permanent power outage. This is important for applications where it is critical to keep track of time, even when the power is off.
One common use for a retentive timer is to track the total run time of a machine. This can be useful for maintenance purposes, as it can help to identify when the machine needs to be serviced. Another common use for a retentive timer is to track the time since a particular event occurred. This can be useful for troubleshooting purposes, as it can help to identify when an error occurred.
