PMC-16AO12-10201 General Standards 16-Bit, 12-Channel, PMC High Speed Analog Output Board

The General Standards PMC-16AO12 16-Bit, 12-Channel, PMC High Speed Analog Output Board contains twelve 16-bit D/A converters (DAC's), and all supporting functions necessary for adding precision high-speed analog output capability to a PCI host. The board is functionally compatible with the IEEE PCI local bus specification Revision 2.3, and supports the "plug-n-play" initialization concept. Unique FIFO buffer controls support the seamless sequencing of successive waveforms. In less demanding applications, the outputs can be updated individually. An optional clock output for synchronizing Sigma-Delta ADC boards is available.

A PCI interface adapter provides the interface between the controlling PCI bus and the internal local controller (Figure 1). Twelve analog output channels are ontrolled through an analog output FIFO buffer, and can be updated either simultaneously or sequentially. The output sample rate can be controlled by an internal rate generator, or by an external clock. The local controller manages all input/output configuration and data manipulation functions, including auto calibration. Analog output levels are initialized to zero (midrange). Multiboard synchronization is supported.

The board is designed for minimum off-line maintenance, and includes internal monitoring 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 50-pin, dual-ribbon front-access I/O connector. Power requirements consist of +5 VDC, in compliance with the PCI specification, and operation over the specified temperature range is achieved with conventional convection cooling.

Selftest networks permit all channels to be calibrated automatically to a single internal voltage reference. Offset and gain trimming of the output channels is performed by calibration DAC's that are loaded with channel correction values during initialization. The correction values are determined during auto calibration, and are stored in nonvolatile EEprom for subsequent transfer to the calibration DAC's. Either auto calibration or initialization can be invoked at any time by asserting a single control bit in the board control register.