The Allen-Bradley 1772-MS8 Segment is an 8K memory segment that adds 8192 binary words of memory to an Allen-Bradley Mini PLC-2 Core Memory Module. It comes as an additional expansion memory PCB segment that enhances the number of operations that can be monitored and controlled from a single PLC-2 processor. The Allen-Bradley 1772-MS8 8K Memory Segment is designed for mounting in any of the 4 sockets present in the Allen-Bradley 1772-ME or 1772-MEB Memory Modules. These are sockets located in the rightmost slot of the processor chassis and they must be pulled out before the memory segment installation process. The electrical power supply must be shut off before mounting or removing memory modules or segments, and even the backup batteries need to be disconnected to avoid damage to the memory modules.

The Allen-Bradley 1772-MS8 8K Memory Segment is keyed to ensure proper installation according to the manufacturer’s installation manual. It has 2 posts on 1 end of the memory segment and only 1 post on the other end. These posts match the holes in the respective memory modules, so that there can never be an incorrect installation. The steps for removing a memory segment like the 1772-MS8 8K Memory Segment from its memory module are as follows: first, remove the system power, remove the right front panel by loosening its thumb screws, remove the memory module at the rightmost slot of the processor chassis, remove and disconnect the battery housing, loosen the memory segment's mounting screws, and pull the segment out. When executing these procedures, it is strongly recommended to use an ESD protection wrist strap, because all the PLC-2 device's internal PCB cards are susceptible to electrostatic damage.