Data Translation DT9837, User Manual

Page: 86 / 150

Chapter 5
86
Triggering Acquisition on Multiple Modules
Note: For DT9837A, DT9837B, and DT9837C modules, you can synchronize acquisition on
multiple modules using the RJ45 (LVDS) synchronization connector, described on page 87 .
The internal clock on the DT9837, DT9837A, and DT9837C modules when the synchronization
mode is none (see
page 87 ), is derived from the USB clock and provides the timing for both the
analog input and analog output subsystems on the module.
You can start acquisition on multiple modules by connecting all modules to a shared external
trigger input, as shown in
Figure 24 . When triggered, the modules start acquiring data at the
same time.
Using this connection scheme, the measurements of one module may not be synchronous with
the measurements of another module due to logic delays in the clocking and USB circuitry.
Figure 24: Triggering Multiple Modules Using an External Trigger Source
Host PC
DT9837
Series #1
USB
Port 1
DT9837
Series #2
USB
Port 2
DT9837
Series #n
USB
Port n
.
.
.
Device Under
Test
External
Trigger
Inputs
Inputs
Inputs