The 1764-MM1RTC is a memory module and a real-time clock that belongs to the 1764 series and it is manufactured and designed by Allen-Bradley. The Allen-Bradley 1764-MM1RTC memory module and real-time clock memory module has 8 Kilobytes memory. The importance of the Allen-Bradley 1764-MM1RTC and real-time clock memory module lies in the fact that it provides a time-base for all the controller functions that require a real-time coordination of events. This module provides the year, month, day of month, day of week, hour, minute, and additional information to the controller. The memory of the Allen-Bradley 1764-MM1RTC and real-time clock memory module stores programs and data, transports programs to be used with other controllers, provides security for critical applications, compares programs, and offers data file and memory module protection.
The accuracy of the real-time clock function can vary significantly depending on its temperature. For a temperature range of 0 to 40 degrees Celsius, the accuracy can vary from 34 to 70 seconds per month and 29 to 75 seconds per month. The battery of the Allen-Bradley 1764-MM1RTC and real-time clock memory module is not replaceable, but this module has a battery indicator, and when it shows that the battery signal is low, it means that the battery will fail within 14 days. The battery life expectancy when operating at a temperature of 0 to 40 degrees Celsius is about 5 years. Both the memory module and real-time clock can be removed without causing damage to the host controller. Once the memory module has been removed and reinserted, the module will not recognize it until a power cycle occurs.