National Instruments NI-488.2 NI-488.2 User Manual page 92

Chapter 8 NI-488.2 Programming Techniques
NI-488.2 User Manual
2. Conduct the parallel poll using
the response for a certain value. In the following example, because
DIO5 is asserted by the device if
bit 4 (hex 10) in the response to determine the value of
PPoll(0, &response);
/* If response has bit 4 (hex 10) set, the ist bit
of the device at that time is equal to 1. If
it does not appear, the ist bit is equal to 0.
Check the bit in the following statement. */
if (response & 0x10) {
printf("The ist equals 1.\n");
}
else {
printf("The ist equals 0.\n");
}
3. Unconfigure the device for parallel polling using
shown in the following example. In this example, the
must appear at the end of the array to signal the end of the address list.
If is the only value in the array, all devices receive the parallel
NOADDR
poll disable message.
AddressList[0] = 3;
AddressList[1] = NOADDR;
PPollUnconfig(0, AddressList);
PPoll,
is 1, the program checks
ist
8-20
store the response, and check
.
ist
PPollUnconfig
NOADDR
, as
constant
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