GE DS3815SSSA

Key Parameters

Serial Communication Section:

• Communication Ports: 2 independent serial ports

• Protocols Supported: Modbus RTU (Master/Slave), GE Mark IV proprietary protocol, ASCII, DNP3, IEC 60870-5-101 (depending on firmware variant)

• Physical Interfaces: RS-232, RS-422, RS-485 (jumper-selectable per port)

• Baud Rates: 300 to 921.6 kbps (software-selectable)

• Function: Gateway for data exchange between Mark IV system and external control networks

• Diagnostics: Per-port LED status (TX/RX/error), communication error counters, signal quality monitoring

Solid-State Output Section:

• Output Channels: 32 or 48 solid-state outputs (depending on configuration)

• Output Type: High-side or low-side solid-state drivers (jumper-selectable per bank)

• Output Voltage: 24V DC or 48V DC (field-selectable per bank)

• Output Current: 0.5A per channel (continuous)

• Diagnostics: Per-channel LED status, short-circuit protection, over-current protection, thermal shutdown, fault feedback to processor

• Response Time: <1ms (turn-on/turn-off)

Common Section:

• Isolation: 2500V RMS channel-to-backplane

• Field Wiring: Integrated terminal blocks for direct field wiring

• Temp Range: –40°C to +85°C (extended)

• Power Supply: +5V (logic), +24V/48V (field power) from backplane or external supply

• Physical: 6U VME single-slot board

• Key Features: Integrated dual serial communication + high-density solid-state outputs, short-circuit protection, adjustable excitation, extended temp range, high isolation

Advantages

• Integrated communication + solid-state outputs – the DS3815SSSA combines dual serial communication and high-density solid-state outputs in a single module, reducing board count and simplifying system architecture.

• Space-saving – replaces up to three separate boards (solid-state output, serial communication, and power distribution) with one module.

• High-speed serial connectivity – the General Electric DS3815SSSA provides Modbus RTU, DNP3, IEC 60870-5-101, and other serial protocols at baud rates up to 921.6 kbps.

• Dual communication ports – allows simultaneous connection to multiple external systems with independent configuration.

• Solid-state outputs – no mechanical contacts to wear out, providing fast, maintenance-free switching (0.5A per channel).

• Bank-configurable – outputs can be configured for high-side or low-side operation and 24V or 48V field voltage.

• Comprehensive protection – short-circuit, over-current, and thermal protection on each channel safeguard the General Electric DS3815SSSA and connected field devices.

• Fault feedback – each channel provides status feedback to the processor, enabling diagnostic monitoring of output health.

• Extended temperature range – operates from –40°C to +85°C for harsh environments.

• High isolation – 2500V RMS isolation protects the backplane from field-side faults.

• Drop-in compatible – works with all Mark IV backplanes and processor configurations.

Applications

• Remote-controlled digital outputs – the DS3815SSSA provides solid-state outputs that can be controlled via DCS or SCADA commands received over serial communication.

• Turbine sequencing and control – drives start/stop commands, solenoid valves, and interlock circuits while communicating with plant-wide control systems.

• Alarm annunciation – drives panel lamps, horns, and DCS alarm outputs with fast, reliable solid-state switching.

• Motor and valve control – controls auxiliary motors, solenoid valves, and isolation valves.

• Distributed control integration – enables Mark IV systems to receive setpoints and commands from external systems while providing output status feedback.

• Offshore and harsh environments – extended temperature range makes it suitable for demanding applications.

• Retrofits – replaces separate solid-state output and communication boards with a single, integrated solution.

vs Competitors & Separate Boards

Selection Tips

• Communication + solid-state outputs – choose the DS3815SSSA when you need both serial communication and high-density solid-state outputs in a single module.

• Slot-limited installations – the General Electric DS3815SSSA reduces board count compared to separate communication and output boards.

• High-speed communication – the 921.6 kbps baud rate is ideal for integration with modern DCS and SCADA systems.

• Dual port requirements – two independent serial ports allow simultaneous connection to multiple external systems.

• Utility SCADA integration – DNP3 and IEC 60870-5-101 protocol support makes it suitable for power utility applications.

• Solid-state preference – provides fast, maintenance-free switching suitable for high-cycle applications.

• Harsh environments – the extended temperature range makes it suitable for offshore, desert, or unheated cabinet installations.

• Spare strategy – keep one DS3815SSSA per 5–8 installed units, especially in systems where communication and control are critical.

• Wiring planning – plan field wiring terminations carefully to leverage the integrated terminal blocks efficiently.

• Calibration – periodically verify communication integrity and output functionality using diagnostic tools.

Critical Precautions

• Output over-current – do not exceed the DS3815SSSA output current rating (0.5A per channel). Overloading can trigger thermal shutdown or damage the output stage.

• Inductive loads – for DC solenoid and relay coil loads, install a flyback diode (for DC loads) across the load to prevent voltage spikes that can damage the General Electric DS3815SSSA output stage.

• Field voltage selection – ensure the DS3815SSSA jumpers are correctly set for 24V or 48V operation before applying field power. Incorrect settings can damage the outputs.

• High-side vs low-side – configure the jumper for high-side or low-side output to match your field device wiring; incorrect configuration can cause malfunction or damage.

• Serial interface selection – ensure the serial port jumpers are correctly set for RS-232, RS-422, or RS-485 before connecting field devices. Incorrect settings can damage the board or connected devices.

• Cable length limits – RS-232: <15 m; RS-422/485: <1200 m. Higher baud rates may require shorter cable lengths.

• Grounding – for RS-485 multi-drop networks, ensure proper termination resistors (120Ω) are installed at each end of the bus.

• Shielded cabling – use shielded cables for serial and output connections. Ground the shield only at the DS3815SSSA end to prevent ground loops.

• Ground loops – use a common return (DC common) for field outputs connected to the DS3815SSSA to avoid floating grounds that can cause false readings.

• Fault handling – if a channel fault is reported, verify the field wiring and load before resetting or replacing the DS3815SSSA.

• Heat dissipation – ensure adequate cabinet cooling (>200 CFM); the DS3815SSSA can generate significant heat under full load.

• Self-test – allow the DS3815SSSA to complete its power-up self-test (~2 seconds) before relying on outputs.

• Calibration intervals – schedule periodic verification (every 6–12 months) to maintain reliable operation.

• Hot-swap – never insert or remove the DS3815SSSA while the rack is powered.

• ESD handling – always use a grounded wrist strap.

• Storage – store spare DS3815SSSA boards in anti-static bags in a dry, temperature-controlled environment.