1. Product Overview

1. Local backplane bus bridging between DPU controller and SUB8 series local I/O rack;

2. RS485 Modbus-RTU serial communication gateway for third-party field instruments, transmit non-Ovation device data to Ovation DPU controller.

   It is widely matched with boiler/turbine auxiliary control cabinet of thermal power plant, petrochemical process DCS system.

2. Core Electrical Specifications

• Working Power: Powered by rack backplane +5VDC / ±12VDC; typical power consumption ≤5W

• Local Bus: Ovation proprietary SUB8 high-speed local I/O bus, single card drives up to 8 slots of SUB8 I/O modules cascaded

• Serial Port: Dual independent RS485 channel, comply with Modbus-RTU protocol; baud rate range 300~38400bps, max communication distance 1200m

• Built-in onboard auxiliary power: 48VDC limited current power supply for dry contact DI field loop wetting

• Protection circuit: Overvoltage, reverse connection, EMC surge, short-circuit automatic protection for bus & serial port

3. Mechanical & Environmental Parameter

• Structure: Standard Ovation European plug-in board for SUB8 I/O rack

• Dimension: 260(L)×100(W)×25(H)mm; Net weight ≈0.36kg

• Operating Temperature: -40℃ ~ +70℃; Storage Temp: -45℃ ~ +85℃

• Working Humidity: 5%~95%RH non-condensing; meets CE industrial EMC certification standard

4. Key Product Features

1. Hot-swap design: Online plug replacement without cutting off cabinet power, no interruption to connected I/O and serial communication equipment

2. Redundancy support: Dual-card redundant backup for critical rack, standby module auto-switchover once main card fault occurs

3. Front panel LED indicators: POWER, BUS RUN, COM STATUS, FAULT four status lamps for rapid field troubleshooting

4. Built-in self-diagnosis: Onboard MCU real-time detect bus offline, serial bus short, communication breakdown, upload fault codes to Ovation DPU for system alarm display

5. Dual application mode: Can be configured either as pure SUB8 local I/O interface or standalone Modbus serial gateway via DCS software configuration

5. Typical Application

1. Thermal power plant boiler feedwater, fan, mill auxiliary control SUB8 local I/O cabinet;

2. Petrochemical unit third-party transmitters, intelligent valve positioner access via Modbus-RTU;

3. Metallurgy, municipal water treatment DCS serial equipment networking with Ovation main control system.

6. Installation & Maintenance Notes

1. Install into designated SUB8 interface slot of Ovation standard rack, lock front panel buckle to avoid loose contact caused by on-site vibration;

2. Important control cabinet config dual redundant 3A99158G01 to improve system uninterrupted operation;

3. Annual maintenance: Clear PCB dust, check backplane golden finger oxidation and RS485 terminal wiring tightness;

4. Prohibit hot plug when RS485 bus is loaded with multiple field instruments to avoid instantaneous surge damage to onboard communication chip.