User`s guide

Universal Library User's Guide Analog Input Boards - USB-2500 Series
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DIO PortNum
For cbDOutScan()/DOutScan() and cbDaqOutScan()/DaqOutScan(), FIRSTPORTA and FIRSTPORTB are
treated as one 16-bit port. These functions can only be used with FIRSTPORTA. You must configure both
FIRSTPORTA and FIRSTPORTB for output using the cbDConfigPort() function.
Synchronous scanning with multiple boards
You can operate up to four USB-2500 Series boards synchronously by setting the direction of the A/D and
D/A pacer pins (XAPCR or XDPCR) in InstaCal.
On the board used to pace each device, set the pacer pin that you want to use (XAPCR or XDPCR) for
Output. On the board(s) that you want to synchronize with this board, set the pacer pin that you want to use
(XAPCR or XDPCR) for Input.
You set the direction using the InstaCal configuration dialog's XAPCR Pin Direction and XDPCR Pin
Direction settings. If you have an older version of InstaCal, these settings might be labeled "ADC Clock
Output" (set to Enabled to configure XAPCR for output) or "DAC Clock Output" (set to Enabled to configure
XDPCR for output).
Wire the pacer pin configured for output to each of the pacer input pins that you want to synchronize.