VTI Instruments EX1629, Руководство пользователя

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EX1629 Introduction 17
Sampling Rate
The EX1629 can be configured for a sampling rate from 1 Sa/s to 10000 Sa/s in 30 discrete
settings, regardless of the number of channels included in the scan list. This permits the tailoring
of the data load to the dynamic requirements of the test application. If the number of channels are
limited, however, a sample rate of 25000 Sa/s may be achieved.
Digital Filtering
Each input provides a programmable digital filter with selectable type, order, and cut-off
frequency. This provides the flexibility to customize the measurement response to the dynamic
and noise rejection requirements of the application.
Triggering
The EX1629 supports a full function trigger model with a separate arm source and trigger source
event structure. Trigger and arm source events can be independently programmed from a variety
of sources including Immediate, Timer, Digital I/O, and the Trigger Bus.
Input Connector
The EX1629 features a standard RJ-45 telecom connector for each input channel. Not only are
these connectors reliable, but low-cost construction of custom length cables is also readily
available. Reconfiguration or replacement of strain gage connections is as easy as connecting a
telephone.
TEDS Transducer Support
The EX1629 provides support to read TEDS-equipped sensors to allow direct input of bridge
configuration parameters and input configuration management.
LXI Trigger Bus
The EX1629 features an LXI (LAN eXtensions for Instrumentation) compatible 8-channel trigger
bus on the rear panel of the instrument. This differential-pair LVDS ( Low-Voltage Differential
Signal ) bus consists of two identical ports connected in parallel. The primary use of the trigger bus
is the transmission of high-speed signals for multiple-unit triggering and synchronization.
LXI Limit Events
LXI Limit Events allow the EX1629 to send triggers to other instruments when an over-limit
condition is detected for bridge measurements. Each of the eight LXI Trigger Bus lines can have a
minimum and/or maximum limit defined for any and all of the 48 bridge measurement channels.
When an over-limit condition occurs, the trigger line is driven high. Because the limit comparison
is performed after filtering, the group delay of the chosen filter also delays trigger assertion. When
all filters are disabled and at a sample rate of 1 kSa/s, the typical delay is 14 ms.
Limit events also allow the user to latch their trigger signal. When latching is enabled, the trigger
line is driven high when the first over-limit condition occurs and remains high until the instrument
is reset or until the next measurement sequence is initiated. When latching is disabled, the state of
the trigger line is decided once per scan. When all chosen limit conditions are satisfied, the line is
driven low. Whenever any limits are exceeded, the line is driven high.