VMIC VMIVME-4120 12 Bit Analog Output Board

Module Feature

VMIVME-4120 is a single-slot 6U VMEbus digital-to-analog converter board developed by VMIC,offering 16 independent analog output channels,each channel can be individually configured via hardware jumpers for voltage mode or 4-20 mA current loop mode,mixed voltage/current configuration is supported on the same board. It features 12-bit DAC resolution with low noise output buffer amplifiers. Voltage ranges include unipolar 0~5 V,0~10 V and bipolar ±2.5 V,±5 V,±10 V. Current loop ranges cover 0~20 mA,4~20 mA and 5~25 mA. The board integrates onboard DC-DC converter to supply isolated analog power;external auxiliary power supply is also available as alternative option. Front-panel P3 connector provides direct field wiring for all analog outputs. VME bus interface supports A16/A24 addressing and D08/D16/D32 data transfer,operating as VME slave module. Built-in BIT diagnostic function can verify DAC conversion accuracy and detect open/short circuit fault on output loops. Rugged Eurocard PCB with conformal coating,shock and vibration screened for power plant cabinet environment,widely used in gas/steam turbine control,industrial process control,test bench and legacy VME real-time simulation chassis.

Working principle

VME host writes digital setpoint values to board registers. DAC chips convert digital codes into analog voltage or current signals. Hardware jumpers define each channel’s output type and full-scale range. Onboard DC-DC generates isolated analog power for current loop excitation. BIT circuit injects reference digital value and measures the analog output to validate channel integrity. VME FPGA performs address decoding and data handshake between host CPU and local DAC register array. Overload protection circuit prevents damage to output amplifier under short-circuit condition.

Onboard components

VME interface FPGA,16 × 12 bit DAC array,output buffer amplifier array,jumper bank for range/type selection,onboard DC-DC converter,current loop excitation circuit,output short-circuit protection network,BIT reference source,VME J1/J2 edge connector,front-panel P3 analog terminal header,multi-status LED array.

LED indicators

Front panel LED indicators for board +5 V power,VME bus activity,BIT fault alarm and analog channel overrange status.

Hardware self-diagnosis

Visual inspection of PCB,front ejectors and solder joints;board ID register readback verification;BIT loopback test for all 16 channels;current loop open/short detection;output range calibration check;VME A16/A24 read/write communication test.

Programming software

VMIC VME device driver library,universal board configuration and BIT diagnostic utility,supports VxWorks,Linux and QNX real-time operating systems;software tool for channel setpoint writing and fault log reading.

Electrical & Process Parameters

Model: VMIVME-4120 Brand: VMIC Device type: 6U VMEbus 16 channel 12 bit analog output module Bus standard: VMEbus, A16/A24 addressing, D08/D16/D32 transfer Resolution: 12 bit per channel Output type: Jumper selectable voltage / current loop, mixed mode available Voltage range: Unipolar 0~5 V / 0~10 V; Bipolar ±2.5 V / ±5 V / ±10 V Current range: 0~20 mA,4~20 mA,5~25 mA Control mode: VME slave access,jumper configurable range,onboard DC-DC,BIT built-in self-test,output short protection Power supply: +5 V from VME backplane,isolated analog power from onboard DC-DC Cooling: Convection cooling Protection: Output short-circuit protection,overrange clamping,ESD protection Mounting: Standard 6U VME front panel ejector locking Protection class: PCB with optional conformal coating

Mechanical & Structure

Mounting: Standard single-slot 6U VME Eurocard Protection class: PCB with optional conformal coating

Environmental

Operating temperature: 0℃ ~ +60℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non-condensing Certification: CE compliant Status: VMIC 16 channel VME analog output board for voltage and current loop

Installation

Follow ESD safety procedure before handling.Fully power off VME chassis.Insert VMIVME-4120 into vacant 6U VME slot and lock front panel ejector latches.Set hardware jumpers for each channel’s output type and range.Wire field actuators and current loop devices to front P3 terminal header.Power on chassis,load VMIC VME driver,run BIT channel diagnostic before commissioning.

Interface

VME J1/J2 backplane connector,front-panel P3 multi-pin analog signal terminal header,fault status signal pins.

Diagnostic

Board undetected: poor VME backplane contact,damaged edge connector or incorrect base address jumper setting. All channel output abnormal: wrong jumper range selection or DC-DC power failure. Individual channel failure: DAC chip fault,amplifier damage or open current loop wiring. Output stuck at full scale: field wiring short circuit.

Product Brief

VMIC VMIVME-4120 single height 6U VME analog output board,16 independent 12 bit DAC channels with jumper selectable voltage and 4-20mA current loop output,equipped with onboard isolated DC-DC power and BIT diagnostic function,for power plant turbine control and industrial process control VME systems.