National Instruments Low-Cost Multifunction I/O Board for ISA Lab-PC+ - Manual (Page 135)

Appendix D Register Map and Descriptions
© National Instruments Corporation D-19 Lab-PC+ User Manual
Start Convert Register
Writing to the Start Convert Register location initiates an A/D conversion.
Address: Base address + 03 (hex)
Type: Write-only
Word Size: 8-bit
Bit Map: Not applicable, no bits used
Note: A/D conversions can be initiated in one of two ways: by writing to the Start Convert
Register or by detecting an active low signal on either the Counter A0 output or the
EXTCONV* signal. If the Start Convert Register is to initiate an A/D conversion, the
Counter A0 output should be initialized to high state, which must be followed by an
ADCLEAR operation, by writing to the ADCLEAR Register.