Siemens 6GK7243-5DX30-0XE0 CP 243-5 AS-Interface Module

The Siemens 6GK7243-5DX30-0XE0 (CP 243-5) is an AS-Interface master communication module for the SIMATIC S7-200 PLC. It connects the S7-200 CPU to an AS-i (Actuator Sensor Interface) network, allowing the PLC to exchange data with up to 62 AS-i slaves (sensors, actuators, small drives). The module also integrates an AS-i power supply (for bus power) and provides 4 digital outputs for local use. It is ideal for decentralised I/O applications in machine building and process automation.

Technical Specifications

The CP 243-5 plugs into the S7-200 expansion bus. Power supply: 24 V DC (from backplane and external). AS-i interface: certified to AS-Interface specification 2.11, supports up to 62 slaves (each with 4 inputs and 4 outputs). Maximum AS-i cycle time: 10 ms for 62 slaves. The module includes an integrated AS-i power supply (24 V DC, 4 A) which powers the AS-i cable and slaves. Additionally, it provides 4 digital transistor outputs (24 V DC, 0.5 A each) that are controlled from the S7-200 CPU. The module has an operating temperature range of 0°C to 55°C. Dimensions: 110 mm × 100 mm × 50 mm. Protection rating IP20. Indicators: LEDs for power, AS-i voltage, AS-i communication, and output status.

Key Features

• AS-Interface master (V2.11 compliant) for S7-200

• Supports up to 62 slaves (extended addressing)

• Integrated AS-i power supply (24 V DC, 4 A)

• 4 digital outputs (24 V DC, 0.5 A) on module

• Data exchange via S7-200 expansion bus (8 input bytes + 8 output bytes)

• Configurable via STEP 7 Micro/WIN software

• Automatic slave address assignment

• Diagnostic functions: AS-i voltage monitoring, slave status

Integration with S7-200

The CP 243-5 is configured as an expansion module in the S7-200 hardware configuration. It consumes 8 bytes of input and 8 bytes of output addresses. The AS-i input data from slaves is mapped to the PLC’s input bytes, and output data is mapped from the PLC’s output bytes. For example, slave address 1 inputs (4 bits) appear at I byte positions. The module also provides diagnostic data in the remaining bytes. The integrated digital outputs on the CP 243-5 occupy the first output byte (e.g., Q byte). The module supports both standard and extended addressing (A/B slaves).

AS-i Network Characteristics

AS-Interface is a simple two-wire bus system (unshielded) that simultaneously carries power (24 V DC) and data. The CP 243-5’s integrated power supply provides up to 4 A to the AS-i cable, sufficient for many small sensors and actuators. The maximum cable length is 100 m per segment (extendable with repeaters). The master cycles through all configured slaves, reading inputs and writing outputs in a deterministic manner. The module also supports safety-oriented AS-i Safety at Work (ASIsafe) with appropriate slave devices.

Installation and Wiring

Insert the CP 243-5 into any available S7-200 expansion bus slot (on the right side of the CPU). Connect the AS-i yellow flat cable (or round cable with adapter) to the AS-i terminal block (two wires: AS-i+ and AS-i-). The module automatically supplies 24 V DC onto the cable. For the integrated outputs, wire loads between the output terminal and ground. The module does not require an external power supply for the AS-i section; the AS-i power is derived from the 24 V DC input to the module (supplied via the backplane). Ensure that the total current draw of AS-i slaves does not exceed 4 A. The module must be grounded via the DIN rail.

Configuration

Using STEP 7 Micro/WIN, add the CP 243-5 module to the project. Specify the number of slaves (automatic detection is possible). The software will allocate I/O addresses. The module’s default AS-i address is 0 (master). The slaves are addressed automatically during configuration using the “Automatic Address Assignment” function. The user program can read/write the I/O bytes as normal digital I/O. The module also supports diagnostic calls to retrieve slave status, peripheral faults, and AS-i voltage.

Applications

Typical applications include connecting distributed sensors (proximity switches, photoelectric sensors) and small actuators (solenoid valves, indicator lights) to an S7-200 PLC without extensive wiring. It is commonly used in packaging machinery, filling lines, and small conveyors where simple, cost-effective decentralised I/O is required.

Environmental and Compliance

The CP 243-5 is CE, UL, and RoHS compliant. It meets EN 50295 (AS-Interface standard). Operating temperature 0-55°C, storage -40-70°C. Humidity 10-95% non-condensing. Vibration 2g (10-55 Hz). IP20 protection.

Conclusion

The Siemens 6GK7243-5DX30-0XE0 CP 243-5 AS-Interface master module allows an S7-200 PLC to communicate with a large number of simple sensors and actuators over a single two-wire cable, reducing wiring effort and cost in small automation systems.