Siemens 6ES7241-1CH30-1XB0 S7-1200 CB 1241 RS485 Communication Board

Siemens SIMATIC S7-1200 CB 1241 communication board with RS485 interface and terminal block connector, designed for point-to-point serial communication. Unlike standard communications modules that mount to the left of the CPU, this board plugs directly into the front of any S7-1200 CPU, preserving control cabinet space.

Supports Freeport, ASCII, Modbus RTU (Master/Slave), 3964(R), and USS protocols. Provides galvanic isolation, integrated diagnostics, and configurable transmission parameters for reliable industrial serial communication.

Applications:

• Modbus RTU network connectivity to sensors, drives, and HMIs

• ASCII data transmission to printers, scanners, or displays

• Legacy system integration with RS485-based equipment

• Point-to-point serial communication between S7-1200 and third-party devices

• Retrofit of existing systems requiring compact communication expansion

Technical Specifications:

• Product type: CB 1241 RS485 communication board

• Interface: RS485 (2-wire, half-duplex), terminal block connector

• Cable length max: 1,000 m (shielded twisted pair)

• Baud rates: 300 to 187,500 bps (300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 187500)

• Protocols: Freeport, ASCII, Modbus RTU (Master/Slave), 3964(R), USS

• Data bits: 7 or 8 bits per character

• Stop bits: 1 or 2 bits

• Parity: None, even, odd, mark, space

• Telegram length max: 1 kbyte (Freeport, 3964R)

• Isolation: Galvanic isolation between interface and CPU logic

• Input current (5V DC backplane): 50 mA (typ.)

• Power loss: 1.5 W (typ.)

• Protection rating: IP20

• Dimensions (W x H x D): 38 mm x 62 mm x 21 mm

• Weight: Approx. 40 g

• Operating temperature: -20°C to +60°C (horizontal), -20°C to +50°C (vertical)

• Storage temperature: -40°C to +70°C

• Diagnostics: Diagnostic function with LED indication

• Certifications: CE, UL, cULus, CSA, FM, RCM, KC, Marine

Compatibility:

• SIMATIC S7-1200 CPUs (all variants: 1211C through 1217C)

• S7-1200 CPU firmware: V2.0 or higher for general operation, V4.1.1 or higher for full Modbus RTU functionality

• TIA Portal V11 or higher

Related Products:

• 6ES7241-1CH30-1XB0 – CB 1241 RS485 (current model)

• 6ES7241-1CH32-0XB0 – CB 1241 RS232 version

• 6ES7241-1AH32-0XB0 – CB 1241 RS232/RS485 combo

For higher channel count or more advanced serial communication requirements, consider CM 1241 communication modules.

Product Status:
Active product. Requires S7-1200 CPU and TIA Portal for configuration.

PLC ERA is an independent industrial automation distributor. Products are sourced through established supply channels and inspected prior to shipment. International shipping available.