VTI Instruments EX1629, Руководство пользователя

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VTI Instruments Corp.
252 EX1629 Command Set
vtex1629_set_dio_output
F
UNCTION
P
ROTOTYPE
ViStatus vtex1629_set_dio_output (ViSession vi , ViInt32 dioOut );
F
UNCTION
P
ARAMETERS
vi = contains a session handle to the instrument. This handle is obtained by the function and remains valid until the
session is closed.
dioOut = an integer input value indicating the programmed output state of the digital I/O. See the Description below
for more information concerning this parameter. Valid input values: 0 to 65535.
D
ATA
I
TEM
R
ESET
V
ALUE
dioOut = 0
D
ESCRIPTION
This function sets the programmed output state for both digital I/O banks. The dioOut parameter is an integer value
that represents the desired state of the digital I/O. This binary value is constructed through the assignment of the
eight most significant bits to the eight channels of bank one (channels 8-15) and the eight least significant bits to the
eight channels of bank zero (channels 0-7). This is illustrated below.
bank one
channel #
bank zero
dioOut
15
0
14
0
13
0
12
0
11
0
10
0
9
0
8
0
7
0
6
0
5
0
4
0
3
0
2
0
1
0
0
0
For example, if a user wants to configure digital I/O channels 2 and 3 of bank zero and digital I/O channels 14 and
15 of bank one as high outputs, then
dioOut should be set to the following:
dioOut = 11000000 00001100b → 0xC00C → 49164
NOTE The control of the digital I/O programmed output state and its direction are disjoint operations.
Thus, the setting of a nonzero output state only affects its actual state if the direction of the
appropriate bank is set to output. This is done with the vtex1629_set_dio_bank0_direction and
vtex1629_set_dio_bank1_direction functions.
E
XAMPLE
ViSession instrumentHandle;
ViStatus status;
…
status = vtex1629_set_dio_output(instrumentHandle, 0x0000C00C);