VTI Instruments EMX-4016B, Руководство пользователя

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VTI Instruments Corp.
APPENDIX B 44
M
ULTIPLE
C
ARDS
, S
EGMENTS
,
AND
C
HASSIS
I
NITIALIZING
D
RIVER WITH
M
ULTIPLE
C
ARDS
Unlike many typical instruments driver, both the Digitizer and DSA drivers treat multiple
EMX-4250/4350/4380 cards as a single, collective instrument. The user can initialize a single driver
for two EMX-4250 cards and treat them as a single, 32 channel instrument instead of creating two
driver sessions with 16 input channels each.
A driver must be initialized first before starting to communicate to with the instruments. The
resource name is passed as an argument to the
Initialize method that specifies which instruments
will communicate. The resource name has the following syntax:
<address 1>[ ::<slot 1>,<slot 2>,..,slot N> ] | <address 2> [ ::<slot 1>,<slot 2>,…,<slot M> ] | …
Where:
<address x> is the IP address or host name of EMX-2500
<slot x> is the slot number identifier of the instrument in a chassis. The slot number identifier is a
string as “slot0_5” indicates 5
th
slot of the first chassis controlled by an EMX-2500. The slot1_6
indicates the 6
th
slot of the 2
nd
chassis extended by a bus extender, the extended chassis is not
supported yet.
The slot numbers are optional. When no slot numbers are specified, all supported instruments within
the chassis will be used.
Where there are more than one EMX-2500 and chassis are involved, they are concatenated with “|”
character.
M
ULTIPLE
C
ARD
M
EASUREMENTS
/ C
OORDINATION
L
INE
A PXI system can be built with more than one bus segment by using standard PCI-PCI bridge
technology. VTI’s CMX18, a eighteen slot chassis, has three independent trigger bus segments,
while the CMX09, a nine slot chassis, has only one PXI trigger bus segment. When all cards included
in a measurement are in single chassis and in a single PXI trigger bus segment, they will be
automatically synchronized using one of the PXI trigger lines on the chassis backplane. The PXI0
trigger line is used by default. Any other PXI trigger line can be specified by
CoordinationLine
property in the Sync interface if the PXI0 trigger line is used by other instruments in a same trigger
bus segment. In multiple cards configuration, the card installed at the lowest slot number becomes
a trigger master and the other cards synchronize to it using a trigger coordination engine
implemented in each instrument. However, in this configuration, any card in the system can detect
an arm or trigger event. For instance, all EMX-4250/4350/4380 cards can be triggered by analog
signal at any one of input channels in the system.