The Siemens 6AV3971-1CA02-0CA0 is a specialized 128 Kbyte memory submodule engineered for the legacy Simatic TD20 operator interface terminal. This module features pre-installed firmware configured for the AS511 communication protocol, enabling reliable data exchange between the TD20 text display and the host programmable logic controller. As a critical component for legacy systems, it ensures the persistence of screen text configurations, system parameters, and variable mappings. Since the official discontinuation of this product in 2005, this module remains an essential spare for maintaining the operational continuity of legacy HMI installations in industrial environments.
Features
Non-volatile EEPROM storage architecture for reliable data retention without battery backup.
Factory-flashed firmware optimized for AS511 point-to-point communication.
Compact plug-in design utilizing a standard 48-pin header interface.
Direct power supply via the host terminal connection (5 VDC).
Designed specifically for compatibility with the Simatic TD20 series terminals.
Applications
This submodule is primarily utilized in legacy automation systems where TD20 terminals are deployed for local process monitoring. Typical applications include mining machinery control, power station HMI interfaces, and legacy manufacturing production lines requiring consistent operator prompt and alarm display functionality.
Technical Specifications
Model
6AV3971-1CA02-0CA0
Brand
Siemens
Product Series
Simatic TD20
Memory Capacity
128 Kbytes
Interface
48-Pin Header
Operating Temperature
0 to 50 deg C
Storage Temperature
-20 to 70 deg C
Power Supply
5 VDC (via host)
Installation Guidelines
Ensure the TD20 terminal is completely powered down before attempting to insert or remove the memory submodule.
Handle the module by its edges to prevent electrostatic discharge (ESD) damage to the internal EEPROM components.
Align the 48-pin header carefully with the expansion slot on the TD20 terminal to avoid bending pins.
Verify that the module is fully seated in the slot to ensure reliable electrical contact.
Store in a dry, temperature-controlled environment when not in use to maintain long-term component integrity.
FAQ
Q: Is this memory module compatible with newer Siemens HMI panels? A: No, this module is specifically designed for the legacy Simatic TD20 terminal and utilizes the AS511 protocol, which is not supported by modern Siemens HMI hardware.
Q: Does this module require a battery for data retention? A: No, the module uses non-volatile EEPROM memory, which retains data even during extended power outages without the need for a battery.
