Acqutek - PA-MD12(16) (details)
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Similar / Related Products PI-IO48A - PA-CP12 - PA-ST12(-H) - PA-MA12(-H) - PA-MD12(16) - PA-AD12(-H) - PA-DA12(16)
XC-IO96 - XC-AD12 - XC-DA12
XI-PI08 - XI-IM04 - XO-RR08 - XO-SRD4/XO-SRA4 - ST-XD02 - ST-DM37 - IC-XCXD

PA-MD12(16) Brief Description
DMA transfer D/A Card

Description - Model No - Expansion - Block Diagram - Function - Register - Programming - Specifications


    DMA data transfer digital to analog card (D/A).
    12 bits converter. (PA-MD12)
    100 KHz digital to analog converter. (PA-MD12)
    50 KHz digital to analog converter. (PA-MD16)
    16 bits conversion. (PA-MD16)
    2 voltage and current analog inputs.


    The PA-MD12(16) is our DMA transfer D/A card for the user that needs fast and reliable data transfers which do not rely

    This high speed converter performs conversion and transfers data using DMA; direct memory transfer. This ensures fast background conversions regardless of the specific computer in use.

    This card provides 2 channels of 12 bit or 16 bit digital to analog conversion (D/A). The conversion time for PA-MD12 is 10 us and 20us for the PA-MD16. Because this card uses the DMA data transfer, no matter what kind of CPU you use, the conversion speed is always the same. (For the PA-MD12 it is 100KHz, for the PA-MD16 it is 50KHz)

    The PA-MD12(16) uses an 8254 timer controller to generate conversion trigger signals. This gives the conversion time more accuracy. The PA-MD12(16) provides the high speed DMA transfer. However, traditional conversion methods are also provided for compatibility purposes


    D/AResolution12 Bit12 Bit
    Conversion time10 us20 us
    Accuracy11 Bit14 Bit


    Model No. Function
    ST-DM37 Screw terminal board for A/D D/A connector
    IC-XCXD Chassis for XCI/XDI expansion cards



    The PA-MD12 provides two voltage and current outputs for 12 bit/16 bit 10us/20us digital to analog conversions.

    Data register - The PA-MD12 uses 4 I/O ports to control D/A conversions. The ports are base+4 through base+7. Using 2 ports per channel enables the user to send a 12-bit word to the D/A converter using an 8-bit bus without getting glitches on the output. Here is an example of the data register scheme. Say a user wishes to convert the digital value from 1AFH to 1B0H to an analog value. Using the standard approach of sending 8 bits at a time would result in a glitch on the output at the digital values 1AFH-1A0H-1BFH(sending LSB first, then MSB) or 1AFH-1BFH-1B0H (sending MSB first, then LSB). However, using the PA-ST12(-H) one would write the 0H (4 least significant bits) to the temporary register (base+4 for channel one and base+6 channel 2). Next the user would write 1BH (8 most significant bits) to the output port (base+5 for channel 1 and base+7 for channel 2). Upon writing the MSB to base+5, the data in the temporary register is automatically sent to the output, thus, both MSB and LSB arrive at the D/A simultaneously (i.e. no glitch).

    D/A conversion - D/A conversion is accomplished using a 12 bit D/A conversion chip. The 12-bit words are sent from the data bus and a temporary register simultaneously. This enables a 12-bit word to be sent from an 8-bit data bus without getting odd glitches on the output.

    DMA Data Transfer - The DMA transfer is the best way to do the D/A conversion. Using DMA transfer not only gives the fastest conversion speeds but also does the conversions in the background leaving the CPU free to do more important jobs.

    The signal connector - The connector for the D/A output signals is the 37 pin male D-type connector. A screw terminal board and a chassis for the screw terminal board are available.


    Port Default DirectionFunction
    +4 02E4H I/O write D/A output 1 LSB data register
    +5 02E5H I/O write D/A output 1 MSB data register
    +6 02E6H I/O write D/A output 2 LSB data register
    +7 02E7H I/O write D/A output 2 MSB data register
    +8 02E8H I/O write D/A command
    +8 02E8H I/O write D/A status port
    +9 02E9H
    I/O Read
    I/O write
    8254 Timer


    Shipped with this board are Utility, Library and Sample Programs. These programs are included with the product at no additional expense.

    Utility Program - This program will provide comprehensive testing of various functions of the board to ensure proper operation.
    Library And Sample Programs - The library program provides the interface to Turbo-C, Microsoft Quick Basic, Microsoft Quick C, Microsoft GW-BASIC, IBM BASIC and Assembler.
    Window Driver - Window 3.1 and Window NT driver interface is available as an optional product.


    Analog Output (D/A)
    Resolution12 bits (PA-MD12)
    16 bits (PA-MD16)
    Output voltage range-5V to +5V, -10V to +10V
    0V to +5V, 0V to +10V
    Output current range-25mA to +25mA
    0mA to +25mA
    Accuracy1 bit (PA-MD12)
    2 bits (PA-MD16)
    Conversion time10 us,100KHz (PA-MD12)
    20 us, 50KHz (PA-MD16)
    Connector37 pins D-type male connector
    Counter Timer (CLK)
    Counters2 for D/A timer conversion
    Clock source4 MHz
    Input/output typeTTL
    Interface Characters
    Compatible busIBM PC and compatibles
    Data path8 bits
    Interface type12 Bit I/O mapped
    I/O location occupied8
    Port address range100H to FF0H
    DMADREQ0, 1, 3
    Power requirement/consumption600mA / +5V
    60mA /+12V and -12V
    Operating temperature+5 ° C to +5 ° C
    Storage temperature-25 ° C to +85 ° C
    Humidity0 to 90% non-condensing
    Weight210 g
    Dimension23.5 x 12.6 x 2.0 cm

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