The custom FAM interfaced with the NI FlexRIO module, which offered low-level digital I/O (3.3 V logic), to digital signal conditioning hardware that provided the 28 VDC signal levels and required current drive.
Each I/O pin was configurable as input or output (source or sink). Each bank of 4 channels had an adjustable threshold level set via an adjustable DAC output. Some of the channels are designed for amp-level current drive, while the remainder were 250 mA. All I/O was fused appropriately.
Viewpoint also developed LabVIEW FPGA and VHDL to enable our client and the end-user to:
- Configure the I/O as in or out.
- Communicate to the DAC to allow custom input threshold trigger levels.
- Read and write the digital data.