Technical Specifications:

• Communication Protocols: RS-232C (V.24), RS-485 (2-wire/4-wire)
• Baud Rate: 300, 600, 1200, 2400, 4800, 9600, 19200, 38400 bps (configurable)
• Connector: 25-pin D-sub male (DB-25M) on module side
• Cable: 12 meters, shielded twisted-pair, with DB-25 connector on far end
• Isolation: 500V AC between communication port and system backplane
• Power Supply: 5V DC from system backplane (no external power required)
• Data Format: 7/8 data bits, 1/2 stop bits, even/odd/no parity (configurable)
• Operating Temperature: 0°C to +55°C
• Dimensions: Eurocard format, 160 mm × 233 mm × 20 mm

Functional Features:

• Supports master/slave communication in RS-485 half-duplex mode
• Up to 31 slave devices on RS-485 bus (with proper addressing)
• Message protocol: Modbus RTU, Yokogawa CBUS, or custom ASCII (configurable)
• LED indicators: TX, RX, ERROR status
• Compatible with CENTUM VP, CENTUM CS, FAST/TOOLS, ProSafe-RS systems

Structural Characteristics:

• Form factor: Eurocard (IEEE 299), single-width
• Weight: approximately 0.25 kg (without cable)
• Cable: 12m shielded twisted-pair, black jacket, oil-resistant

Working Principle:
The SC25V module receives data from the DCS controller via the system backplane bus. A UART (Universal Asynchronous Receiver/Transmitter) converts parallel data to serial format. For RS-485, an RS-485 transceiver (e.g., MAX485 or equivalent) converts TTL-level signals to differential RS-485 signals. The 12m cable transmits the differential signal to the external device. Isolation is achieved via opto-couplers or digital isolators between the backplane and communication port.

Advantages & Highlights:

• Built-in 500V AC isolation protects the DCS from surges on the communication line
• 12m pre-terminated cable eliminates field wiring errors
• Multi-protocol support enables integration with third-party devices
• No external power supply required; powered from backplane
• LED diagnostics simplify troubleshooting

Applicable Industries:
Oil & Gas, Chemical, Power, Water Treatment, Building Automation, Manufacturing

Installation Requirements:

• Install in DCS I/O card cage (Eurocard slot)
• For RS-485 multi-drop: use 120 Ω termination resistor at each end of the bus
• Cable routing: maintain minimum 100 mm separation from power cables (>100V)
• Connect shield to chassis ground at one end only (DCS end recommended)
• Verify baud rate, parity, and address settings match the external device

Usage Precautions:

• Do not connect RS-232C and RS-485 devices to the same port simultaneously
• For RS-485, maximum cable length is 1200m at 9600 bps; this module provides 12m segment
• Do not exceed ±15V on RS-232C lines
• Use surge protector if the communication line is exposed to lightning-prone areas
• Do not bend the cable below 30 mm radius