Siemens 6ES5377-0AA31 Memory Submodule

This memory submodule provides non-volatile storage for Siemens SIMATIC S5 automation systems. It stores user programs and data tables for S5 CPUs. Therefore, it eliminates battery dependency for critical application code preservation.

Physical and Memory Specifications

The Siemens 6ES5377-0AA31 measures 6.5 cm in length and 5.0 cm in width. Moreover, its submodule weight equals approximately 0.03 kg for easy installation. A single 32-pin edge connector interfaces directly with the S5 CPU card. Additionally, this memory submodule uses Flash EPROM technology for permanent data retention.

Parameter	Specification
Brand	Siemens
Full Model	6ES5377-0AA31
Category	MEMORY SUBMODULE (Flash EPROM)
Dimensions (L x W x H)	6.5 cm x 5.0 cm x 0.8 cm (2.56″ x 1.97″ x 0.31″)
Submodule Weight	0.03 kg (0.07 lbs)
Interface Type	1 x 32-pin Edge Connector
Memory Type	Flash EPROM (NOR)
Memory Capacity	64 kB
Program Storage	64 kB (User Application Code)
Read Access Time	150 ns (Typical)
Write Endurance	100,000 Cycles (Minimum)
Erasure Method	Electrical (In-System or External Programmer)
Data Retention	10 Years (Minimum at 55°C)
Battery Requirement	None (Non-Volatile)
Compatible CPUs	S5 115U, 135U, 155U
Programming Voltage	5 VDC / 12 VDC (External Programmer)
On-Board Components	1 Flash Memory Chip + 1 Write Protection Jumper + 4 Decoupling Capacitors
Energy Storage	4 x 0.1 µF Ceramic Capacitors (Decoupling Only)
Operating Voltage	5 VDC (from CPU Slot)
Power Consumption	0.08 W (Typical)
Operating Temperature	0°C to +55°C (32°F to 131°F)
Storage Temperature	-40°C to +85°C (-40°F to 185°F)
Write Protection	Jumper (On Submodule PCB)
UV Erasure Window	None (Electrically Erasable)

Memory Architecture and Non-Volatile Storage

The Siemens 6ES5377-0AA31 uses Flash EPROM technology for permanent data retention. Specifically, NOR Flash architecture allows byte-level read access for fast program execution. In addition, this memory submodule requires no battery backup for data preservation. Moreover, the submodule retains stored programs for up to 10 years without power. Consequently, you can store critical application code safely without periodic battery changes.

Hardware Write Protection and Installation

A hardware jumper on the submodule PCB enables write protection. Specifically, setting the jumper prevents accidental overwrites during operation. In addition, you can erase the submodule electrically using an external programmer. Furthermore, the submodule plugs directly into the S5 CPU’s memory socket. Thus, field technicians can replace the submodule without special tools.

Flash Technology Advantages Over EPROM

Unlike standard UV-EPROMs, this submodule uses electrical erasure for convenience. For instance, you do not need a UV eraser or opaque window covers. In addition, the 100,000 write cycles allow frequent program updates in the field. Moreover, the absence of a quartz window makes the submodule more robust. Therefore, the Siemens 6ES5377-0AA31 suits applications requiring periodic program changes.

Compatibility and Usage Instructions

This memory submodule works with S5 115U, 135U, and 155U CPUs exclusively. For example, it fits into the memory expansion socket on these processor cards. In addition, the 64 kB capacity stores up to approximately 4000 ladder logic statements. However, do not remove the submodule while the CPU has power applied. Thus, always power down the S5 rack before inserting or extracting this submodule.