Chapter 4
Arb Operation
©
National Instruments Corporation
4-21
DAQArb 5411 User Manual
Output Enable
You can switch off the waveform generation at the output connector by
controlling the output enable relay, as shown in Figure 4-17. When the
output enable relay is off, the output signal level goes to ground level.
Note:
Even though the output enable relay is in the off position, the waveform
generation process will continue internally on the DAQArb 5411.
You can use this feature to disconnect and connect different devices, on
the fly, to the DAQArb 5411.
Note:
You can change the output enable state at any time during waveform
generation.
Pre-attenuation Offset
Pre-attenuation offset is an offset adjustment to the waveform before
the attenuation chain. You can adjust the pre-attenuation offset,
provided you have at least 10 dB of attenuation switched in. With a
terminated load, you get a ±2.5 V offset adjustment before the
attenuation chain.
With less than 10 dB of attenuation switched in, you can also adjust the
pre-attenuation offset as much as ±2.5 V (into 50
Ω
), provided that the
waveform maximum plus offset before attenuation does not exceed
±5 V (into 50
Ω
).
Note:
The pre-attenuation offset is also attenuated by the attenuation setting you
specify through the software.
For example, if you have waveform generation into a terminated load
with 20 dB attenuation, the output levels are ±0.5 V. If you set up a
pre-attenuation offset of +1 V, the actual offset you will see at the
output connector is +0.1 V (20 dB of +1 V).
Note:
You can change the pre-attenuation offset at any time during waveform
generation.
