Siemens 6ES5985-1AA11 EPROM Memory Submodule

The 6ES5985-1AA11 stores firmware and fixed program data for SIMATIC S5. This submodule plugs into memory slots on S5 CPUs and function modules. It retains data permanently without any backup battery.

Key Technical Specifications

Parameter	Value
Memory Type	UV-EPROM (erasable)
Memory Capacity	16 KB (128 Kbits)
Access Time	250 ns typical
Supply Voltage	5V DC from host module
Supply Current	30 mA maximum
Programming Voltage	12.5V external
Erase Method	UV light, 254 nm wavelength
Erase Time	20 minutes typical
Submodule Dimensions	3.2 cm x 2.8 cm x 0.8 cm
Weight	0.02 kg (0.04 lbs)
Component Count	2 ICs + socket
Operating Temperature	0°C to 60°C

Physical Dimensions and Component Layout

This submodule measures 3.2 cm in length and 2.8 cm in width. Its total height reaches 0.8 cm including the component body. 6ES5985-1AA11 weighs only 0.02 kg for easy handling. You will find one EPROM chip and one address decoder IC on a small PCB.

Moreover, the submodule includes a quartz window on top of the EPROM. This window allows UV light to erase the memory contents. A protective label covers the window during normal operation.

Memory Architecture and Access

The EPROM chip stores 16 KB of firmware or fixed user data. You can write to this memory only with a special programming device. The CPU reads the memory with a 250 ns access time. Consequently, the submodule supports fast program execution without wait cycles.

Connector Interface and Installation

A 28-pin dual-inline connector plugs into the host module socket. The submodule aligns with a keying slot to prevent incorrect insertion. You can install or remove it without any special tools. A small extraction notch helps you lift the module from its socket.

Typical Application Scenarios

You can deploy 6ES5985-1AA11 in SIMATIC S5-115U, 135U, and 155U systems. It also works well for S5-100U and S5-90U compact controllers. This submodule stores operating system firmware and fixed machine recipes. Its permanent storage suits applications requiring tamper-proof program retention.