6ES7340-1BH02-0AE0 20mA TTY CP340 Communications Processor

Key Features and Technical Specifications

The 6ES7340-1BH02-0AE0 is designed for dependable serial communication in SIMATIC S7-300 systems. Below are the core specifications extracted from the official datasheet:

• Interface: 20 mA (TTY), isolated, 1 interface
• Transmission rate: 2.4 to 19.2 kbit/s
• Cable length: 100 m active, 1,000 m passive
• Connector: 9-pin sub D socket
• Protocols: 3964(R), ASCII, printer drivers (HP-Deskjet, HP-Laserjet, IBM-Proprinter, user-defined)
• Max telegram length: 1,024 bytes (3964(R) and ASCII)
• Power supply: Via backplane bus 5 V DC
• Current consumption: 190 mA max from backplane bus
• Power loss: 0.85 W typ., 0.95 W max
• Ambient temperature: 0 to 60 °C operation; -40 to 70 °C storage
• Dimensions: 40 mm x 125 mm x 120 mm
• Weight: approx. 300 g

One distinctive feature is the isolated TTY interface, which protects the PLC from ground loops and voltage spikes that can occur over long cable runs.

Applications and Use Cases

The 6ES7340-1BH02-0AE0For example, it can link a PLC to a weigh scale in a remote part of a plant, or connect to a barcode scanner at a loading dock. Because it supports printer drivers, it can also drive industrial printers for labeling or reporting without requiring a PC in between. The 3964(R) protocol is widely used in Siemens environments, ensuring seamless integration with existing S7-300 programs.

Installation and Setup

Mounting the CP340 is straightforward. The module fits onto a standard S7-300 DIN rail and connects to the backplane bus for both power and communication. Ensure the bus connector is properly seated to maintain the 5 V DC supply. For the TTY connection, use a 9-pin sub D plug and observe the correct pinout for active or passive operation. When using passive mode, the maximum cable length is 1,000 m; for active mode, limit the cable to 100 m. Always follow the wiring diagram provided in the manual to avoid signal errors.

Maintenance and Reliability

Because the TTY interface is isolated, the module is less prone to damage from electrical transients, which contributes to long-term reliability. Still, periodic inspection is recommended. Check that all connectors are tight and free from corrosion, especially in humid or dusty environments. The operating temperature range of 0 to 60 °C means the module can be installed in most industrial cabinets without additional cooling, but ensure adequate airflow around the module to prevent overheating.

Solving Long-Distance Serial Communication Challenges

The 6ES7340-1BH02-0AE0 from Siemens addresses this with a 20 mA (TTY) interface that supports cable runs up to 1,000 meters in passive mode. This CP340 communications processor ensures stable, isolated point-to-point connections even in electrically noisy industrial environments.

Compatibility and Integration

The 6ES7340-1BH02-0AE0 is part of the SIMATIC S7-300 family and is compatible with all S7-300 CPUs that support CP340 communication modules. It uses the 3964(R) and ASCII protocols, which are standard in Siemens automation. The included configuration package on CD simplifies setup within the TIA Portal or STEP 7 environment. For custom printer drivers, the module supports user-defined drivers, offering flexibility for specialized equipment.

Troubleshooting Common Issues

If communication fails, first verify the transmission rate matches the connected device. The module supports 2.4 to 19.2 kbit/s, but the actual rate must be set identically on both ends. Check the cable length: exceeding 1,000 m in passive mode can cause signal degradation. Also confirm the connector type is a 9-pin sub D and that the wiring is correct. If using a printer, ensure the printer driver is properly loaded. For persistent issues, consult the Siemens manual or contact AutoDCSTech for technical support.

Product Support and Availability

The 6ES7340-1BH02-0AE0 is available through AutoDCSTech. Contact our team to confirm current stock and lead times.