VTI Instruments EX1401, Руководство пользователя

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82 EX1401 Instrument Drivers
F
IGURE
5-7: LAN C
OORDINATION
Before enabling LAN coordination, each EX1401 and EMX-2500 controller must be configured to
use PTP2 as the time source (see Time Configuration
in Section 4). All devices must use the same
value for the PTP Domain. They must also be configured to use the same value for LXI Domain via
the web page or using the Platform driver.
After opening the Digitizer/DSA driver session, the ReferenceOscillator.Source and
ReferenceOscillator.TimestampSource properties must be set to “System” (IEEE 1588). The
Sync.Line property must be set to a comma-separated list of sources for the sync signal, such as
“ALARM0” or “ALARM0,PXI0”. The
Sync.CoordinationLine property must be set to a comma-
separated list of signals (beginning with “LAN”) to use for the coordination subsystem, e.g., “LAN”
or “LAN,PXI0”. Note that EMX devices require specifying a hardware line in addition to LAN
when setting the
Sync.CoordinationLine property. See the Digitizer/DSA driver documentation for
more information.
The most convenient way to ensure the correct settings for synchronization/coordination is to
configure the desired arm sources, events, and trigger sources, then call the
Sync.AutoConfigure
method. This selects the best values for the Sync.Line and Sync.CoordinationLine properties based
on the devices in the driver session. See the Digitizer/DSA driver documentation for more
information.
LAN coordination may cause unexpected confusion in rare circumstances if the devices are
separated by a long distance or network communication is slow. For example, when an analog
channel detects a trigger, it sends a LAN message to all devices so that they trigger at the same time.
If another channel from a different device also detects a trigger condition before it receives the LAN
event from the device that detected the previous trigger condition, the multiple triggers cannot be
processed correctly. In order to avoid this scenario, the user may need to set restrictions so that only
certain channels can detect trigger events.
IEEE1588
Grandmaster
Ethernet LAN
IEEE1588 Clock
IEEE15
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GPS
Host PC
EX1401 (1)
EX1401 (n)
EMX-2500