Siemens 6ES5377-0AB31 Memory Submodule

The 6ES5377-0AB31 expands the program memory of SIMATIC S5 CPUs. This submodule plugs directly into the memory slot on S5 processors. It stores user logic, data blocks, and system parameters securely.

Key Technical Specifications

Parameter	Value
Memory Type	Static RAM (SRAM)
Memory Capacity	4 KB
Supply Voltage	5V DC from CPU backplane
Supply Current	35 mA typical
Backup Battery	3.6V lithium (external)
Data Retention	300 days with fresh battery
Access Time	150 ns
Submodule Dimensions	5.0 cm x 3.5 cm x 1.0 cm
Weight	0.03 kg (0.07 lbs)
Component Count	8 integrated circuits
Energy Storage	None (external battery)
Operating Temperature	0°C to 60°C

Physical Dimensions and Component Layout

This submodule measures 5.0 cm in length and 3.5 cm in width. Its total height reaches 1.0 cm including the edge connector. 6ES5377-0AB31 weighs only 0.03 kg for easy handling. You will find 8 ICs and several passive components on a two-layer PCB.

Furthermore, the submodule includes a socket for an external backup battery connection. This battery maintains memory contents when the system powers off. The PCB uses gold-plated edge contacts for reliable connections.

Memory Architecture and Access

The SRAM chip provides 4 KB of read-write programmable storage. You can store up to 2000 instructions and 200 data words. The CPU accesses this memory with a 150 ns access time. Consequently, the submodule supports fast scan cycles without wait states.

Connector Interface and Installation

A 64-pin gold-plated edge connector plugs into the CPU memory slot. The submodule aligns with keying slots to prevent incorrect insertion. You do not need any tools for installation or removal. A plastic ejector latch helps you remove the submodule safely.

Typical Application Scenarios

You can deploy 6ES5377-0AB31 in SIMATIC S5-115U, 135U, and 155U systems. It also works well for S5-100U compact controllers needing extra memory. This submodule stores ladder logic, statement lists, and function block data. Its 4KB capacity suits medium-sized automation tasks like conveyor control.