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ProDAQ 3430 4-Channel Sigma-Delta Function Card 
The ProDAQ 3430 is a four-channel sigma-delta ADC board. Every channel contains a front-end conditioning circuitry followed by a sigma-delta ADC. The bit stream from every ADC is then directed to FIR decimation filters. There are up to 10 stages of the FIR filters, which are connected serially. The user has the possibility to select how many stages of the FIR filters are active. The filtered data from the selected stage is then stored in the FIFO. The data from the FIFO can be moved on-the-fly to the Motherboard or to the host. The 3430 can be configured to work either independently or it can be synchronized with other 3430 boards. The multi-board synchronization requires that the same sampling clock and sync signals are distributed to all 3430 boards. The 3430 offers a very flexible solution for Data acquisition systems requiring Sigma-Delta ADCs. This function card offers both programmable single ended and differential inputs terminated with either 50 Ohm or 1MOhm. The input gains are programmable on a per channel basis offering ranges between ± 10V and ± 0.10V. The of measurement resolution is 16 bit allowing 305µV on the ± 10V range. The front end filtering makes use of an active 6 pole Bessel filter with a -3dB point of 312.5kHz (500 kHz for the -Bx versions). This design prevents ringing, especially on square waves, traditionally associated with analogue input stages. Also, being an linear phase filter, this results in an equal delay of all frequencies. The inputs are protected against shorts up to ± 35V DC making this a robust solution and tolerant of accidental errors. The Sync Input, which is used to synchronize multiple 3430 channels, is programmable between -2V and +5V in 1024 steps. This can be routed between boards allowing intra board synchronization. The Trigger input level is programmable between -2V and +5V in 1024 steps. In the single ended mode each channel can be corrected using the 10 bit offset DAC up to a maximum of ± 5V in 1024 steps. This allows signals to be brought in range or to be zeroed. The internal fixed sample clock runs continuously at 5MHz resp. 8MHz, which together with the 8x oversampling results in an output data rate of 625kHz in the -Ax versions and 1MHz in the -Bx versions. Alternatively an external clock input is available per board. This facilitates synchronization to an external clock source. Each channel is relay isolated allowing disconnection without physically having to remove the connector. The 3430 operates in full capability with full functionality on the ProDAQ 3180 Ultra-performance Motherboard and the ProDAQ 3150 High-performance Motherboard and with reduced functionality on the ProDAQ 3120 Standard Motherboard. The 3120 only supports 16 bit mode. The 3430 consumes two adjacent function card slots within a motherboard and up to 4 off 3430s can be fitted onto a motherboard offering up to 16 channels per VXI slot. The vacant slots on a motherboard can be populated with other function cards from the ProDAQ range. The 3430 and 3150/3180 motherboard system is able to sustain a 625kHz sampling rate. Data samples are block moved from the 3430 FIFO onto the 64MB motherboard memory and made available to the Slot-0 controller. ProDAQ modules provide compatibility with all current popular software environments and allow users to safely and simply expand their existing hardware and software systems.
The supplied driver automatically detects
and initializes all function cards installed into
a ProDAQ Motherboard Module, removing
any possibility of configuration errors.
The ProDAQ 3430 Sigma-Delta
Function Card is supplied with VXIplug&play
drivers for the WIN95 and WINNT frame-works.
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