Siemens 6AV6640-0AA00-0AX1 TD400C Text Display for S7-200: Specifications and Replacement Guide

The Siemens 6AV6640-0AA00-0AX1 is a SIMATIC TD400C text display designed for use with Siemens SIMATIC S7-200 PLC systems. It provides a compact operator interface for displaying machine messages, process information, and operating parameters.

Featuring a four-line backlit STN graphic display, an RS485 PPI communication interface, and a customizable keypad supporting up to 15 keys, the Siemens TD400C is suitable for existing S7-200 automation installations.

For industrial maintenance engineers, machine manufacturers, and spare-parts buyers, identifying the exact Siemens part number is important when sourcing a replacement for an existing operator display.

The Siemens 6AV6640-0AA00-0AX1 belongs to the SIMATIC TD400C text display family. It is designed to communicate with SIMATIC S7-200 controllers through an RS485 PPI interface.

Unlike a modern touchscreen HMI, the TD400C uses a text-based display and physical membrane keys. This design makes it suitable for machine installations where operators need to view status messages, monitor process values, and interact with predefined operating functions.

The TD400C can be configured with STEP 7-Micro/WIN V4 SP6.

Specifications are based on Siemens TD400C documentation. Actual installation protection depends on correct panel mounting and sealing.

The Siemens TD400C is a compact operator interface for the SIMATIC S7-200 PLC platform.

In an industrial machine, operators need a way to view information from the PLC and interact with predefined machine functions. A text display provides this interface without requiring a large graphical touchscreen.

The TD400C can be used to display information such as:

• Machine operating status

• Production messages

• Process values

• Alarm and diagnostic messages

• Operating instructions

• Parameter information

Its physical keypad allows operators to navigate configured screens and execute predefined functions.

For older automation equipment that still uses Siemens S7-200 controllers, maintaining the original TD400C interface can help preserve the established machine operation environment.

The TD400C features a backlit STN graphic display with a resolution of 192 × 64 pixels.

Its four-line format allows machine information and operating messages to be presented in a compact layout.

The backlight helps operators read displayed information in different industrial working environments.

The Siemens TD400C supports a customizable faceplate with up to 15 keys.

The membrane keypad provides physical controls for interacting with configured machine functions.

This is useful in applications where operators prefer dedicated keys instead of touchscreen operation.

The 6AV6640-0AA00-0AX1 communicates with the SIMATIC S7-200 through an RS485 PPI interface.

The documented communication rates are:

• 9.6 kbit/s

• 19.2 kbit/s

• 187.5 kbit/s

When replacing an existing TD400C, confirm the communication settings and PLC configuration before installation.

The TD400C has a nominal supply voltage of 24 V DC, with a documented operating range of 15–30 V DC.

Before connecting the display, check the power supply polarity, voltage, and wiring arrangement against the Siemens manual.

The TD400C is designed for panel installation.

According to Siemens documentation, the front-mounted device can achieve IP65 protection when the specified installation requirements are followed. The rear housing is rated IP20.

Correct mounting, gasket condition, panel thickness, and screw tightening are important for maintaining the specified front-panel protection.

The TD400C can provide a local operator interface for machines controlled by Siemens S7-200 PLCs.

Operators can view configured messages and interact with predefined functions.

Packaging machines often require compact operator displays for production status, operating instructions, and alarm information.

A text display can provide these functions without the need for a larger graphical HMI.

Existing production equipment may use the TD400C as the operator interface for monitoring machine conditions and viewing process information.

The compact panel-mount design makes the TD400C suitable for control cabinets where operators need a simple text-based display.

Many industrial facilities continue to maintain existing S7-200 installations.

For these systems, identifying the correct TD400C part number can be important when repairing or maintaining the original operator interface.

When replacing a Siemens TD400C, do not select a display based only on its appearance or screen size.

Check the following details before ordering:

1. Complete part number: Confirm 6AV6640-0AA00-0AX1 on the original label.

2. PLC compatibility: Verify that the machine uses the compatible SIMATIC S7-200 platform.

3. Communication interface: Confirm RS485 PPI requirements.

4. Display configuration: Check the four-line display and 192 × 64 resolution.

5. Key configuration: Verify the required keypad and customized faceplate.

6. Power supply: Confirm the 24 V DC nominal supply and wiring.

7. Software: Check the existing STEP 7-Micro/WIN configuration environment.

8. Mounting dimensions: Compare panel cutout and installation requirements.

9. Accessories: Confirm cable length, mounting accessories, and other items required by the original installation.

10. Program backup: Preserve the existing configuration and machine project before replacing the display.

A newer HMI may offer additional functions, but it should not automatically be treated as a direct replacement. Software, communication, mounting, and PLC compatibility must be checked first.

The Siemens TD400C is configured using STEP 7-Micro/WIN V4 SP6.

When maintaining an existing installation, engineers should consider the following:

• Keep a backup of the original PLC project.

• Record the current TD400C configuration.

• Check the PPI communication settings.

• Inspect the communication cable and connectors.

• Verify the 24 V DC power supply.

• Check the display backlight and keypad operation.

• Confirm that the configured messages and function keys operate correctly after replacement.

These checks can help reduce commissioning problems and unnecessary machine downtime.

Industrial automation buyers often search for spare parts using the exact manufacturer part number.

For the Siemens TD400C, relevant search terms include:

• Siemens 6AV6640-0AA00-0AX1

• 6AV6640-0AA00-0AX1 TD400C

• Siemens TD400C text display

• Siemens S7-200 text display

• Siemens S7-200 operator panel

• Siemens four-line text display

• Siemens TD400C replacement

• 6AV6640-0AA00-0AX1 spare part

• Siemens SIMATIC TD400C

• Siemens RS485 PPI display

These keyword variations cover exact-model searches, product-category searches, and replacement-related purchasing intent.

For industrial facilities operating older Siemens S7-200 equipment, finding the correct operator display can be an important part of maintenance planning.

A faulty display or keypad may affect the operator's ability to monitor machine conditions and interact with the PLC.

Before sourcing a replacement, buyers should confirm the full Siemens order number, communication interface, display configuration, and included accessories.

The Siemens 6AV6640-0AA00-0AX1 TD400C is a specific model reference for customers maintaining existing S7-200 systems.

For product details and availability inquiries, visit the corresponding product page at CXY Trade PLC.

Siemens 6AV6640-0AA00-0AX1 is a SIMATIC TD400C four-line text display designed for Siemens S7-200 PLC systems.

The TD400C uses a backlit STN graphic display with a resolution of 192 × 64 pixels.

The TD400C supports a customizable faceplate with up to 15 keys.

It uses an RS485 PPI interface, with documented communication rates of 9.6, 19.2, and 187.5 kbit/s.

The TD400C is configured with STEP 7-Micro/WIN V4 SP6.

Confirm the full part number, S7-200 compatibility, PPI communication settings, power supply, keypad configuration, mounting requirements, and accessories.

The Siemens 6AV6640-0AA00-0AX1 TD400C is a compact four-line text display designed for SIMATIC S7-200 automation systems.

With its 192 × 64 backlit STN display, customizable keypad supporting up to 15 keys, RS485 PPI communication, and 24 V DC supply, it remains a relevant identification reference for maintenance and spare-parts sourcing in existing S7-200 installations.

When searching for a replacement, always verify the complete Siemens part number:

6AV6640-0AA00-0AX1

Checking the original configuration and machine documentation helps ensure the correct operator interface is selected.