Description
Emerson 3A99158G01
Technical Specifications
- Number of output channels: 8 analog output channels
- Output signal: 4-20mA current signal
- Isolation between channels and backplane
- Operating ambient temperature: 0℃ ~ 60℃
- Storage temperature: -40℃ ~ 85℃
- Relative humidity: 5% ~ 95%, non-condensing
- Backplane communication: Ovation DCS dedicated bus
- Channel loop fault detection function
Functional Features Digital to analog conversion circuit converts controller command into stable 4-20mA current signal for field control devices. Channel isolation reduces cross interference between different output loops. Built-in loop diagnosis detects open circuit and short circuit of field wiring. Front panel LED indicators show each channel running status and fault. Rack plug-in structure supports hot swap under non-critical process condition.
Application Scenarios Ovation DCS cabinets in thermal power plants and chemical plants. It outputs analog control signals to control valve positioners, frequency converters and field indicators.
Performance Parameters
- Digital-analog conversion maintains high signal accuracy in full temperature range
- Channel isolation prevents cross-talk between different analog output loops
- Loop fault detection identifies wiring abnormality rapidly
- Output current keeps high stability under rated load resistance
Material Composition Flame-retardant engineering plastic housing. Multi-layer flame-retardant glass fiber epoxy PCB. Digital-analog conversion chips, isolation components, current drive circuits and LED indicators. Gold-plated copper alloy backplane connector. Matching terminal base uses flame-retardant PA plastic and nickel-plated copper screw terminals.
Structural Features Standard plug-in card for Ovation DCS rack slots. Front panel equipped with module fault LED and independent LED indicators for each output channel. Guide rails and mechanical latches lock module inside rack. Rear gold-plated connector mates with Ovation rack backplane bus. Front terminal base connects field control device cables.
Working Principle Ovation controller sends digital setpoint command to module through DCS backplane bus. Onboard digital-analog conversion chip converts digital value into corresponding 4-20mA current signal. The current signal outputs to field control devices through terminal base. Sampling circuit monitors output loop current continuously. When open circuit or short circuit is detected, module generates fault alarm and uploads to DCS operator station.
Installation Requirements Insert module along rack guide rail into Ovation DCS slot and lock mechanical latch. Use shielded twisted pair cables for field control device wiring, shield single-point grounding inside cabinet. Separate analog signal cables from high-voltage power cables. Reserve air circulation space around module.
Precautions for Use Cut off field instrument power before wiring. Set output range parameters in DCS engineering station before commissioning. Inspect loop wiring tightness regularly. Do not short output terminals in normal operation. Verify output signal accuracy after module replacement. Do not disassemble module housing.
