PMC-ADADIO-312 General Standards 12-Channel 16-Bit Analog I / O PMC Card

The PMC-ADADIO board is a single-width PMC module which contains eight 16-Bit A/D converters, four 16-bit D/A converters, and all supporting functions necessary for adding flexible analog I / O capability to a PMC host. The board is designed for minimum off-line maintenance, and includes internal monitoring and loopback features that eliminate the need for disconnecting or removing the module from the system for calibration. All analog input and output system connections are made through a single 68-pin subminiature-D front-access I / O connector. The analog outputs can be internally disconnected from the system I / O connector under software control.

Offset and gain trimming of the 16-bit ADC and output DAC's is performed by 24 12-bit DAC's. System analog inputs pass through a selftest network which can replace the system signals either with a precision voltage standard or with the four analog output channels, under software control. This arrangement is used during autocalibration to determine the offset and gain correction parameters for the ADC, and for each of the output D/A converters. The correction parameters are stored in a calibration EEPROM for subsequent transfer to the calibration DAC's during board initialization. Autocalibration can be invoked at any time from the PCI bus.

Each analog output channel is accessed through an independent 16-bit data register in PCI memory space. ADC conversion data are read by the bus through an analog input FIFO buffer. An auxiliary digital port contains eight bits of bidirectional data and two control lines, and is controlled through a single register.

Communication with the host PCI bus is provided by a PCI Interface Adapter which furnishes a 32-bit local bus for exchanging information between the FIFO buffers, the adapter, and the Local Controller. All internal operations are managed by the Local Controller.