GX1648 Geotest Analog Output Board

The Marvin Test Systems / Geotest GX164x Series Analog Output Boards are organized as four groups with each group having 16 channels each. The GX1642 / GX1648 channels have 12-bit D/A converters (DAC). The GX1649 has 16-bit D to A converters. Each group can be independently set to one of the four available voltage ranges: 0-10V, ±10V, 0-5V or ±5V for the GX1642. The GX1648 supports 0-20V, ±20V, 0-10V or ±10V ranges. A single range of ±15V is supported for the GX1649. Changing the voltage range (GX1642/GX1648 only) will change the group's channels voltage resolution. For example changing the range from ±10V to 0-5V will change the resolution from 4.88mV to 1.22mV. All channels will source or sink a minimum of 10mA of supply current for all voltage ranges. In addition to static output channels, the GX1649 has 256K of sample memory for each group which can be used to generate waveforms. Each of the four channel groups can be configured as a waveform generator or as static outputs.

The board has a local controller that performs all internal configuration and data manipulation between the PXI bus and the board. Values are first loaded to the specified channel output buffer before being programmed to the corresponding DAC. Each DAC has an output buffer enabling users to load all (or part) of the board's channels with new values and then updating all outputs at once.

The local controller reads the 16-bit channel data value for each channel from the analog output buffer, and sends the value serially to the associated output DAC. The output DAC holds this value in an internal buffer until commanded to transfer the data to the output register that drives the DAC output. All output registers are updated simultaneously.