The Allen-Bradley 1764-RTC is an RTC module featuring a real-time clock that is for use with the MicroLogix 1500 series of controllers. The output source of this module is a relay port and DC FET and it uses 7 KB worth of memory, specifically 3.56 KB for the user program and 4 KB user data, when installed on the 1764-LSP and 14 KB made up of 10 KB for the user program and also 4 KB for the user data when used with the 1764-LRP. Its enclosure rating is the IP20 and to make the battery last, make sure that the storage temperature of the 1764-RTC module falls within the -40 to 40 °C range, as higher temperatures will shorten the battery life, which averages 5 years in normal conditions.
This module features a two-piece design that consists of the processor and base unit which are independently replaceable and that slide together and only takes up a minimal footprint. The 1764-RTC module is used for establishing a time-base for a MicroLogix 1500 controller that need coordination with real-time events. This clock provides the following information: second, minute, hour, the day of the week, the day of the month, month, and year. Users can install or remove the 1764-RTC module even while the controller is running without interrupting its operation. However, this module will not be immediately recognized and it will only be recognized when it is in a non-executing mode, specifically on the program mode or fault condition, and after a power cycle.