Measurement Computing CIO-CTRxxHD - Manual (Page 7)

addresses, then 300-31F HEX are free to use. Address not specifically listed, such as
390-39F, are usually free.
3.2 INTERRUPT LEVEL SELECT
A single interrupt input at pin 26 allows you to initiate an interrupt service routine
with an external pulse. The interrupt level is selected via software and is one of the
options set in the InstaCal configuration file.
3.3 CLOCK SOURCE SELECT
The source of the pulses supplied to the 9513 for timing operations is programmable
and there are a number of options. These options are shown in the InstaCal INSTALL
screen.
3.4 INSTALLING THE CIO-CTR##HD IN THE COMPUTER
Turn the power off. Remove the cover of your computer. Please be careful not to
dislodge any of the cables installed in your computer as you slide the cover off.
Locate an empty expansion slot in your computer.
Push the board firmly down into the expansion bus connector. If it is not seated fully
it may fail to work and could short circuit the PC bus power onto a PC bus signal.
This could damage the motherboard in your PC as well as the CIO-CTRHD.
The CIO-CTRxxHD connector is a 50 pin header type connector. All the signals from
the 9513 and interrupt are accessible. Pin one is designed by a square solder pad. It is
the pin on the PC Bus end of the connector, and closest to the edge of the card.
Cables C50FF-2 and the CIO-MINI50 allow easy connection to all of the counter
signals through 12-22 AWG screw terminals. The CIO-CTR20HD has two of these
connectors, P1 and P2. The signals on each are identical.
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