Advantech iDAQ-900 Series, User Manual

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iDAQ-900 User Manual 16
3.1 Function Details
The iDAQ system relies on the chassis module as a platform to aggregate all the sig -
nals together, in order to achieve functions including synchronization, data streaming
and timing control. This chapter describes all the functions that the iDAQ systems
provide and how they work.
3.2 Trigger and Signal Routing
3.2.1 Signal Routing
When performing hardware-timed acquisition or update, the start and stop of the
acquisition, and the timing for acquiring input samples and updating output samples
are all controlled by an acquisition engine.
Each slot on iDAQ-934 has its own acquisition engine, which means every slot can
use different timing signals (start trigger, stop trigger, and sample clock) to perform
independent acquisition tasks. For example, one of the slots may be acquiring analog
input data at 200 kS/s sample rate using an analog input module, and another slot
may be acquiring digital input data at 10 kS/s sample rate using a digital input mod -
ule. Each task can be started and stopped independently.
Each timing signal may come from one of various sources as shown in Figure 3.1. If
multiple slots use the same source for timing signals, they can perform synchronized
acquisition. The following sections describes the routing of these timing signals.
Figure 3.1 Signal routing of an acquisition engine.
There is also an acquisition state signal generated by the acquisition engine for inter-
chassis synchronization.