The Allen-Bradley 1771-HMA memory cartridge is a CMOS memory cartridge. It is mainly used with IMC 120 systems. It is a lithium-ion battery-backed memory module from Allen-Bradley/Rockwell Automation. This memory cartridge has a memory capacity of 96 KB. The battery produces a current of 1700 mAh and it has a voltage rating of 3.6 Volts DC. The main function of this memory cartridge is to provide a backup source of power. It is mainly used for industrial memory applications. It uses a 3-pin connector terminal to connect to devices. The 1771-HMA memory cartridge is also used for storing the MML programs and the AMP parameters.

The Allen-Bradley 1771-HMA memory cartridge operates within a temperature range of 0 to 60 degrees Celsius and it can be stored at 0 to 60 degrees Celsius. The required humidity level for operation should be maintained between 5 and 95% without condensation. The 1771-HMA memory cartridge comes with a MARINE certification. The cartridge should not be used in or near places where there is a high amount of electrostatic discharge. This discharge is known to damage or degrade the performance of the module. The CMOS memory cartridge has a maximum lifespan of 10 years. It is possible to use the low self-discharge feature of the battery. During the installation of the memory cartridge, the battery should be turned ON by changing the rocker switch SW1 to the BAT ON position. The 1771-HMA memory cartridge has a red “system” LED which alerts the users in the case of a failure so they can enable the battery. If the “motion controller” LED does not power up (the green LED) when power is applied or when the “memory” LED turns on, the connector pin should be checked.