Advantech iDAQ-817, User Manual

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17 iDAQ-817_821 User Manual
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Buffered analog output waveform generation has several advantages over static ana -
log output update:

The start and stop time of generation (or duration of the generation) can be pre -
cisely controlled by hardware trigger signals.

DAC conversion rate is configurable, and update rate can be much higher by
using hardware sample clock signal.

Time between samples is deterministic.
3.3.3 Analog Output Isolation
Each channel is equipped with a galvanic isolator, which can withstand a large con -
tinuous voltage between external side and internal side. This prevents the internal
components and the host devices (e.g. PC) from damaging when such fault condition
happens.
3.3.4 Analog Output Fail-safe Function
When upstream communication is disconnected, the value of the analog output
channels cannot be controlled by the software anymore and will keep at the last
value before disconnection. This may cause harmful operation for the external
devices which is begin controlled by the analog output channels.
The analog output fail-safe function can be enabled to solve this problem. If enabled,
the value of the analog output channels will be automatically set to the pre-pro -
grammed fail-safe values when disconnection occurs. After reconnection, the value
can again be controlled by the software.
3.4 Device Description and Configuration
The Device Description is used to differentiate the modules in the iDAQ system. It's
given following a naming rule of combining chassis ID, model name and slot number.
You can change the description in Navigator, or just leave it as default. The descrip -
tion is used in your own program, in order to get control or device handler from the
device.