The VXC/VEX-142 series card provides two RS-422/RS-485 serial ports. Each port can be configured as either RS-485 for half-duplex or RS-422 for full-duplex communication. It supports for speed up to 115200 bps and supports full-duplex communication.

Users may specify a COM port number manually by setting dip switch, or let the driver choose an available number automatically. The driver provides a maximum of 128 KB software FIFO for each COM port under Windows. It’s practical for large file transmission.

The data lines of each serial ports on i version VXC/VEX cards come with photocouplers design. The on-board photo couplers use a short optical transmission path to transfer a signal between elements of a circuit, and keep the data lines electrically isolated. It can help cutting down on ground loops, common mode voltages and block voltage spikes, provide electrical isolation, and offer significant protection from serious over-voltage conditions in one circuit affecting the other.

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    • Industrial Machinery
    • Building Automation
    • Restaurant Appliances
    • Laboratory Equipment & Research
    • Industrial Communication


    • Supports 3.3 V/5 V PCI bus, Plug and Play for VXC-142(i)AU
    • Supports PCI Express, Plug and Play for VEX-142(i)
    • Provides 2 RS-422/485 ports
    • Built-in COM-Selector
    • +/-4 kV ESD Protection for i versions
    • 2500 VDC Isolation for i versions
    • 128 KB Software Buffer (max.) for Each COM Port Under Windows
    • 128-byte Hardware FIFO for Each Port
    • Short Card Design


    • Windows NT4/2000 drivers for VXC series.
    • Drivers for 32-bit Windows XP/2003/2008/7/8/10
    • Drivers for 64-bit Windows XP/2003/2008/7/8/10
    • Driver for Linux

    Hardware Specifications

    Models VXC-142AU VXC-142iAU VEX-142 VEX-142i
    Communication Port
    COM1 ~ COM2 RS-422/485 The RS-422 and RS-485 cannot be used simultaneously
    RS-422 TxD+, TxD-, RxD+, RxD-, RTS+, RTS-, CTS+, CTS-, GND
    RS-485 2-Wire Data+, Data-, GND
    Bias Resistor Yes, 1 KΩ
    Node 256 (max.)
    UART 16C950 compatible
    Baud Rate 50 – 115200 bps
    Data bit 5, 6, 7, 8
    Stop bit 1, 1.5, 2
    Parity None, Even, Odd, Mark, Space
    FIFO Internal 128 bytes
    Isolated 2500 VDC 2500 VDC
    Bus Type Universal PCI, 3.3 V and 5 V, 33 MHz, 32-bit, Plug and Play PCI Express x1, Plug and Play
    COM-Selector Yes (8-bit DIP switch)
    Connector 2 x DB9 (Male)
    Power Consumption 100 mA @ 5 V 480 mA @ 5 V 120 mA @ 5 V 440 mA @ 5 V
    Operating Temperature 0 °C ~ +60 °C
    Storage Temperature -20 °C ~ +70 °C
    Humidity 0 ~ 90% RH, non-condensing
    Dimensions (L x W x D) 134 mm x 90 mm x 22 mm 110 mm x 94 mm x 22 mm

    Ordering Informations

    PCI Express Bus
    VEX-142 CR PCI Express Bus, Serial Communication Board with 2 RS-422/485 ports (RoHS)
    VEX-142i CR PCI Express Bus, Serial Communication Board with 2 Isolated RS-422/485 ports (RoHS)
    Universal PCI Bus
    VXC-142AU CR Universal PCI Bus, Serial Communication Board with 2 RS-422/485 ports (RoHS)
    VXC-142iAU CR Universal PCI Bus, Serial Communication Board with 2 Isolated RS-422/485 ports (RoHS)


    vxc-142_vex-142 series


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