VMIC MC-650 Counter / Timer Board

Module Feature

MC-650 is a single-slot 6U VMEbus high performance counter/timer board developed by VMIC (GE Fanuc). It integrates eight independent 32-bit counter channels,each channel supports quadrature encoder A/B/Z phase input for rotary position tracking. Input signal mode can be set as single-ended or differential by software configuration. Hardware capture latch freezes counter value instantly upon external trigger signal to record precise position timestamp without CPU intervention. Onboard digital filter eliminates input signal bounce and high-frequency noise. All I/O signals are routed to VME P2 rear connector for rear transition panel wiring. Front panel equipped with trigger activity LED and module fault indicator. Built-in BIT self-test injects internal pulse signals to verify counter register and input circuit integrity. Rugged Eurocard PCB with conformal coating,shock and vibration screened for power plant cabinet environment,widely used in gas/steam turbine rotary encoder signal collection,aerospace ground test bench and hardware-in-loop real-time simulation VME chassis.

Working principle

Encoder A/B phase pulses feed into the channel input circuit; quadrature decoding logic counts pulse and judges rotation direction. Z index signal resets or latches counter value for origin alignment. When external hardware trigger arrives,hardware latch captures current counter value and stores data in read register. BIT test generates internal pulse sequence to each counter channel and compares readback count value against expected value to validate function. VME FPGA handles base address decoding,register read/write and interrupt generation after capture event. Input filter suppresses contact bounce and electromagnetic interference from field sensor wiring.

Onboard components

VME interface FPGA,eight 32-bit counter register banks,quadrature decode logic,hardware sample latch bank,digital de-bounce filter array,internal pulse test source,BIT diagnostic hardware,VME J1/J2 edge connector,P2 rear I/O signal pins,front-panel status LED array.

LED indicators

Front panel LED indicators for trigger capture active and module fault alarm.

Hardware self-diagnosis

Visual inspection of PCB,components and solder joints;board ID register readback verification;BIT pulse count loopback test for all 8 channels;VME A16 register communication validation.

Programming software

VMIC counter driver library and configuration utility,supports VxWorks,Linux and QNX real-time operating systems;software tool for quadrature mode setup,filter parameter configuration,hardware latch enable and BIT fault log reading.

Electrical & Process Parameters

Model: MC-650 Brand: VMIC (GE Fanuc) Device type: 6U VMEbus 8 channel 32-bit quadrature counter / timer module Bus standard: VMEbus, A16 short addressing, D08/D16/D32 data transfer Channel:8 independent 32-bit counter channels Input type: Single-ended / differential selectable,quadrature A/B/Z encoder Max input frequency: 10 MHz per channel Control mode: VME slave access,hardware position latch,digital input filtering,quadrature direction detection,BIT closed-loop pulse test,input surge clamping Power supply: +5 V from VME backplane Cooling: Convection cooling Protection: Input ESD and overvoltage clamping Mounting: Standard single-height 6U VME front panel ejector locking Protection class: PCB with optional conformal coating

Mechanical & Structure

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

Environmental

Operating temperature:0℃ ~ +70℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:20~80% non-condensing Certification: CE compliant Status: VMIC 6U VME high-speed 8-channel 32-bit quadrature counter timer board

Installation

Follow ESD safety procedure before handling.Fully power off VME chassis.Insert MC-650 into vacant 6U VME slot and lock front panel ejector latches.Set onboard DIP switch for base address.Configure input mode (single-ended/differential) via software.Mate rear transition board to P2 connector and connect encoder shielded wiring.Power on chassis,load VMIC counter driver,run BIT diagnostic before commissioning.

Interface

VME J1/J2 backplane connector,P2 rear multi-pin encoder signal connector,capture trigger and fault status register pins.

Diagnostic

Board undetected: poor VME backplane contact,damaged edge connector or incorrect DIP address setting. BIT count test failure: input circuit abnormality or counter register fault. Wrong rotation direction: A/B phase wiring swapped or quadrature mode misconfiguration. Lost pulse count: missing digital filter or input frequency exceeding module max rating.

Product Brief

VMIC MC-650 single height 6U VME counter timer board,eight 32-bit quadrature encoder channels with hardware position latch and digital de-bounce filter,built-in BIT pulse self-test,provides high-precision rotary position capture interface for turbine shaft encoder monitoring and aerospace hardware-in-loop simulation VME systems.