VTI Instruments EX1401, User Manual

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EX1401 Instrument Drivers 73
individually. Querying the current setting through channel groups works only when all channels are
set to the same value.
The channel name is defined as <slot no>!CH<channel no>. For example, 2!CH2 indicates the 2nd
channel of a card installed at slot2 of a chassis. The predefined channel group names are “ALL” or
an instrument model number such as “EX1401”. Optionally, the user can create new custom channel
groups using
AddChannelGroup method. When more than one instrument are in the session, the
channel name of the 2
nd
instrument adds 100 to the slot number, such as 102!CH2, and 200 for the
3
rd
instrument, 300 for the 4
th
, etc. The RX0124 and RX0224 instruments each consist of only one
digitizer slot, slot 2, to maintain compatibility with EMX products. The EX1401 instrument consists
of a single digitizer slot called inst0.
The NumChannels property gives the total number of individual input channels, while the Count
property is the total number of channel or channel group objects in the array.
S
TART
, A
RM
, T
RIGGER
,
AND
A
LARM
The EX1401 implements a sophisticated Arm/Trigger model as show in Figure 5-1. This trigger
model conforms to industry stand trigger models defined in the IVI Digitizer specification and IVI
LXI Sync specification, with some additional features.
F
IGURE
5-1 T
RIGGER
M
ODEL