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MTL 8202-HO-IS
Product Name: PAC8000 8-Channel Intrinsically Safe Analog Output Module, 4–20 mA with HART
Product Introduction: This module drives eight intrinsically safe 4–20 mA output loops into hazardous areas for control valves, I/P converters, positioners and recorders. HART pass-through allows configuration and diagnostics of smart final elements without interrupting the analog control signal.
Detailed content
Technical Specifications: 8 isolated analog outputs; 4–20 mA nominal; 12-bit resolution; load resistance 0–650 Ω; compliance voltage minimum 13 V at 20 mA; system current 630 mA; open-circuit fault detection; channel-to-Railbus isolation 60 V AC; response 80 ms standard, 1 s in HART mode.
Functional Features: HART variable and status pass-through; configurable output initialization; configurable fail-safe drive; open-circuit detection; short-circuit limiting through IS entity parameters; per-channel activation and alarm configuration.
Performance Parameters: Accuracy ±20 μA at 25 °C; temperature stability ±0.006 % span per °C from -40 to +70 °C; IS entity open-circuit voltage and short-circuit current must be matched to field device certification; typical open-circuit detection above approximately 685 Ω depending on configuration.
Material And Structure: Industrial IS enclosure with conformal coating; 42 mm module width class; PAC8000 carrier or DIN-rail mounting; plug-in field terminal; galvanic isolation barrier between field loop, Railbus and logic power.
Working Principle: The Railbus sends digital output commands to the DAC. Each channel produces a current-limited 4–20 mA signal through an IS barrier stage. HART FSK signaling is superimposed on the current loop so the controller can read device diagnostics while maintaining analog control.
Installation Requirements: Install in PAC8000 IS carrier with approved IS field terminal; verify module key code; calculate total cable capacitance, inductance and resistance within entity limits; separate IS and non-IS wiring; use shielded cable with shield grounded according to the system earthing design.
Application Scenarios: Valve positioners in chemical plants, I/P converters in pneumatic systems, burner fuel-air actuators, hazardous-area recorder loops and oil-and-gas offshore control rooms.
Usage Precautions: Do not connect non-IS actuators to IS output channels. Do not exceed maximum loop resistance for the required 20 mA compliance. Verify HART device power demand against module compliance voltage. De-energize the IS Railbus segment before module replacement where plant procedure requires it.
