The Schneider Electric T200 RTU COM (Part Number: CT00126-06) is a specialized Communication Module designed for the T200 Remote Terminal Unit (RTU). This module acts as the critical interface for enabling Modbus Master communication, allowing the RTU to poll, collect, and manage data from downstream intelligent electronic devices (IEDs), sensors, and power monitoring hardware in distribution automation networks.

📋 Technical Specifications

• Module Type: Modbus Master Communication Interface
• Compatibility: Schneider Electric T200 / T200I Series
• Supported Protocols: Modbus RTU / ASCII (Master mode)
• Connector Type: RJ45 or Screw Terminal (dependent on sub-revision)
• Dimensions: 110mm x 90mm x 45mm
• Weight: 0.30 kg
• Country of Origin: France / EU

 

⚙️ Mechanical Installation Requirements

• Mounting Method: Plugs directly into the communication expansion slot on the T200 RTU backplane. Ensure the retention clips are fully engaged to prevent loosening due to cabinet vibrations.
• Spatial Clearance: Ensure at least 30mm of clearance around the module to allow for the routing of shielded communication cables without creating sharp bends.
• Thermal Dissipation: No active cooling required. Ensure the RTU enclosure provides adequate passive ventilation, maintaining an internal operating temperature between -25°C and +70°C.

 

⚡ Electrical Wiring & Connectivity

• Terminal Definitions:
  • TX+/RX+ (Data A): Modbus non-inverting signal
  • TX-/RX- (Data B): Modbus inverting signal
  • GND (Shield): Signal ground reference
• Wire Gauge Requirements: Use high-quality 24 AWG (0.2mm²) shielded twisted-pair (STP) cabling for RS-485 connections.
• Grounding Specifications: Connect the cable shield to the ground terminal at the RTU end only to prevent ground loops. Ensure the RS-485 segment is terminated with a 120Ω resistor at both physical ends of the bus.

 

📡 Communication Configuration

• IP Address: N/A (Serial Modbus Master operates on RS-485 addressing, not IP).
• Station Number (Node ID): Set the RTU’s master ID (typically 0 or 1) in the RTU configuration software.
• Baud Rate/Framing: Set via the T200 configuration tool (e.g., 9600, 19200, or 38400 bps). Ensure data parity (Even/Odd/None) and stop bits (1 or 2) match the slave devices connected to the bus.

 

❓ Frequently Asked Questions (Q&A)

• How do I verify if the module is communicating? Observe the “TX” and “RX” status LEDs on the front panel. Flashing green indicates successful data exchange; if the lights are off, check your bus wiring and address settings.
• Can this module handle multiple Modbus slaves? Yes, as a Modbus Master, the CT00126-06 can address up to 32 standard unit loads on a single RS-485 segment without a repeater.
• What happens if a slave device times out? The T200 RTU will log a communication alarm in the system event buffer. You can configure the retry count and timeout duration in the Master polling configuration software.
• Is the communication port isolated? Yes, the RS-485 interface is galvanically isolated to protect the T200 processor from potential surges on the communication line.