VTI Instruments Corp.
274
EX1629 Command Set
The
dioLines
parameter is an array of four elements with each array element being an unsigned 8-bit integer. Each
bit of this integer corresponds to a digital I/O channel. Specifically, the least significant bit corresponds to a digital
I/O channel zero, and the most significant bit corresponds to digital I/O channel seven. Each element specifies which
events the EX1629 will accept as trigger events on the digital I/O bus for different clock edges or states. If a user
wants to specify a channel for trigger events, the corresponding bit should be set to “1”. Specifically, the individual
array elements specify the following:
0 = dioLines[0] Positive Edge
1 = dioLines[1] Negative Edge
2 = dioLines[2] Positive Level
3 = dioLines[3] Negative Level
For example, if a user wishes to trigger the EX1629 on a negative edge signal coming into the digital I/O bus on
channels 0 and 3, then:
dioLines[1]
= 00001001 = 0x09 = 9.
With regard to the
lxiOutput
parameter, it is important to note that since the EX1629 can simultaneously accept
trigger events from multiple sources, it is necessary to reserve one of the LXI Trigger Bus line to communicate these
events within the device and to other devices in a multi-device configuration. If the EX1629 is a master driving
trigger events to peripheral slaves, the
lxiOutput
parameter specifies the LXI Trigger Bus line that will be used to
communicate the trigger event to the slave devices. It is also necessary to configure this LXI Trigger Bus line to be
used as an output (see vtex1629_set_lxibus_configuration).
The
lxiInput
parameter specifies which trigger bus line the master device uses for its trigger events. Although this
parameter is often set to the same value as
lxiOutput
, there are cases where it might be set to a different value. For
instance, when the device is configured as a master device in a star multi-box configuration, the master might output
the trigger event on LXI2 and input it back in on LXI6.
Decimal
Value
Hex
Value
#define Symbol
lxiOutput/lxiInput
Description
0
0x00
VTEX1629_LXI_LINE_ZERO
LXI LINE 0
1
0x01
VTEX1629_LXI_LINE_ONE
LXI LINE 1
2
0x02
VTEX1629_LXI_LINE_TWO
LXI LINE 2
3
0x03
VTEX1629_LXI_LINE_THREE
LXI LINE 3
4
0x04
VTEX1629_LXI_LINE_FOUR
LXI LINE 4
5
0x05
VTEX1629_LXI_LINE_FIVE
LXI LINE 5
6
0x06
VTEX1629_LXI_LINE_SIX
LXI LINE 6
7
0x07
VTEX1629_LXI_LINE_SEVEN
LXI LINE 7
8
0x08
VTEX1629_LXI_LINE_NONE
None
E
XAMPLE
ViSession instrumentHandle;
ViStatus status;
ViInt16 triglines[VTEX1629_MAX_LINES];
ViInt16 diolines[VTEX1629_MAX_LINES];
…
triglines[0] = 0x00;
triglines[1] = 0x01;
triglines[2] = 0x48;
triglines[3] = 0x00;
diolines[0] = 0x0000;
diolines[1] = 0x0009;
diolines[2] = 0x0000;
diolines[3] = 0x0000;
status = vtex1629 vtex1629_set_pattern_trigger_configuration (instrumentHandle,
triglines,
diolines,
VI_FALSE,
VTEX1629_LXI_LINE_THREE,
VTEX1629_LXI_LINE_THREE);
