VMIC VMIVME-4140 Analog Output Board

Module Feature

VMIVME-4140 is a single-slot 6U VMEbus analog output board developed by VMIC,equipped with 32 independent 12 bit DAC channels,each channel has dedicated digital-to-analog converter. Multiple voltage ranges are fully software configurable without hardware jumper change.Unipolar options include 0~2.5 V,0~5 V,0~10 V;bipolar ranges cover ±2.5 V,±5 V,±10 V.Each channel can source/sink up to ±10 mA with typical 0.8 Ω output impedance. It adopts dual-buffered output architecture,supporting random non-scan update,software synchronized update or external hardware trigger synchronous update. The board integrates DSP for automatic gain and offset calibration;calibration coefficients for each channel and each voltage range are saved in onboard RAM. Built-in BIT diagnostic circuit can disconnect analog outputs from field wiring to perform offline test,also supports continuous online status monitoring. Front panel LED indicators report power,bus activity and fault alarm. VME interface supports A16/A24 addressing and D08/D16/D32 data transfer,works as VME slave device. Rugged Eurocard PCB with conformal coating,shock and vibration screened for power plant cabinet environment,widely used in gas/steam turbine control,hardware-in-loop real-time simulation,process control and aerospace test VME chassis.

Working principle

VME host writes digital values to board register,data is latched in dual buffer memory. When sync trigger arrives,DAC converts digital data to analog voltage simultaneously. DSP executes auto-calibration sequence to measure gain and offset error of every channel,then stores correction coefficients for real-time compensation during normal operation. BIT circuit can switch output relay to isolate field wiring and run closed-loop test on DAC channels. VME bus interface FPGA completes address decoding and data handshake. Short-circuit protection circuit prevents damage to DAC chip when field output is shorted.

Onboard components

VME interface FPGA,32 × 12 bit dedicated DAC array,DSP calibration controller,dual-buffer RAM,output relay isolation network,short-circuit protection circuit,nonvolatile coefficient storage RAM,output buffer amplifier array,VME J1/J2 edge connector,front panel analog signal 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 fault status.

Hardware self-diagnosis

Visual inspection of PCB,front ejectors and solder joints;board ID register readback verification;DAC channel auto-calibration routine;BIT offline loopback test for all 32 channels;output short protection 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 range setup,calibration trigger and fault log reading.

Electrical & Process Parameters

Model: VMIVME-4140 Brand: VMIC Device type: 6U VMEbus 32 channel 12 bit analog output module Bus standard: VMEbus, A16/A24 addressing, D08/D16/D32 transfer Resolution: 12 bit per channel Voltage range: Unipolar 0~2.5 V / 0~5 V / 0~10 V; Bipolar ±2.5 V / ±5 V / ±10 V Max channel current: ±10 mA Output impedance: 0.8 Ω typical Control mode: VME slave access,dual buffered output,auto calibration,BIT built-in self-test,output short protection Power supply: +5 V from VME backplane 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℃ ~ +70℃ Storage temperature: -40℃ ~ +85℃ Ambient humidity: 5~95% non-condensing Certification: CE compliant Status: VMIC 32 channel 12 bit VME analog output board

Installation

Follow ESD safety procedure before handling.Fully power off VME chassis.Insert VMIVME-4140 into vacant 6U VME slot and lock front panel ejector latches. Wire analog field actuators to front terminal header. Power on chassis,load VMIC VME driver,run auto-calibration and BIT channel diagnostic before commissioning.

Interface

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

Diagnostic

Board undetected: poor VME backplane contact,damaged edge connector or incorrect base address setting. Analog output drift: calibration coefficient loss or aging of output amplifier. BIT channel failure: DAC chip fault or isolation relay malfunction. No synchronous update: wrong external sync wiring or software trigger configuration error.

Product Brief

VMIC VMIVME-4140 single height 6U VME analog output board,32 independent 12 bit DAC channels with software-selectable voltage ranges,dual-buffered synchronous update and auto-calibration BIT function,for power plant turbine control and hardware-in-loop real-time simulation VME systems.