Triggering Acquisition On Multiple Modules - Measurement Computing Data Translation DT9857 User Manual

Chapter 5

Triggering Acquisition on Multiple Modules

Note: You can synchronize acquisition on multiple DT9857 or DT9857E modules using the
Sync Bus, described on
The internal clock on the DT9857 and DT9857E modules when the synchronization mode is
none (see
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
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 36: Triggering Multiple Modules Using an External Trigger Source
104
page
page 105), is derived from the 48 MHz crystal oscillator and provides the timing for
Figure
Device Under
Test
Inputs
External
Trigger
Inputs
Inputs
105.
36. When triggered, the modules start acquiring data at the
DT9857
#1
DT9857
#2
.
.
.
DT9857
#n
Host PC
USB USB USB
Port 1 Port 2 Port n