User manual

Series 3700 System Switch/Multimeter Reference Manual Section 11: LXI Class B Triggering (IEEE-1588)
3700S-901-01 Rev. C / July 2008 11-9
Synchronizing multiple Series 3700 instruments
NOTE Synchronization only occurs between instruments within the same
PTP subdomain. Use ptp.subdomain to set the subdomain name.
Refer to Configuring and enabling IEEE-1588 (on page 11-3) for
further details.
To execute synchronized actions on multiple Series 3700 instruments, you must
connect these instruments to a network using Ethernet and enable IEEE-1588
protocol. Refer to Configuring and enabling IEEE-1588 (on page 11-3) for details
on how to enable IEEE-1588 protocol.
The protocol aligns the timebases of each of these instruments. You need to
enter a delay in your software application to allow for this synchronization to
complete. Synchronization to within 150ns can take as long as two minutes for
system alignment. You can read the current time delay and offset between any
slave device and its master on the LAN using ptp.ds.current. Refer to
IEEE-1588 Implementation in the Series 3700 (on page 11-1) for information on
the time synchronization process.
After you enable IEEE-1588 and set up alarms, configure the action to occur at
the firing of the alarm. Use the event identifiers for the scheduled alarms,
schedule.alarm[x].EVENT_ID (on page 13-250), as the stimulus for the
control sources in the trigger model.
Coordinating the Series 3700 with a device that is not IEEE-
1588 enabled using scheduled alarms and digital I/O
If you have a network where the Series 3700 is the only IEEE-1588 enabled
device, you can trigger actions on the other networked devices by means of
digital triggers if such devices can process digital triggers. In this way, you can
schedule alarms to execute switch-only or switch with DMM operations on the
Series 3700 and you can also output triggers to other devices at the firing of the
scheduled alarms.