New Features Supported on NI PXIe-54x3 Waveform Generators

A new feature of the PXIe-54x3 devices is the ability to open multiple sessions with the same device. This allows you to utilize each channel as an independent device. Due to this new approach, sessions will behave differently on PXIe-54x3 devices in the following ways:

• To output signals on multiple channels at the same time, you must create a separate independent session for each channel.
• It is still possible to create multi-channel sessions. However, the PXIe-54x3 devices do not allow writing a waveform to a single channel when in multi-channel mode. To work around this, consider the following options:
  • Write interleaved data for each of the channels, effectively generating a different waveform on each  channel.
  • Create an independent session for each channel and output a different signal in each session.

• If a session is running a calibration procedure, no other sessions on the device can generate a waveform until the calibration is complete. Even though independent sessions can be created on PXIe-54x3 devices for each channel, the device cannot be calibrated on a channel by channel basis. Because of this, when a calibration procedure is being run, no channels can be generating signals.
• Performing a device reset on one session will abort waveform generation on all other sessions.

There are some differences with timing and clocks to consider when migrating to PXIe-54x3 devices from previous arbitrary waveform generators.

• The PXIe-54x3 devices support the internal clock on the device or the 100MHz PXI backplane clock, but do not support external clock sources.
• The PXIe-54x3 devices only support High-Resolution clock mode which uses direct digital synthesis to generate very fine resolution  increments on the order of microhertz. This provides finer control over possible sample rates that can be used in your applications.  
• The minimum sample rate that can be achieved on the PXIe-5413 and PXIe-5423 with the digital filter disabled is 3.125 MS/s. The PXIe-5433 supports setting the sample rate to 10 S/s with digital filter disabled like previous arbitrary waveform generators.

*It is possible to output lower frequency signals with the PXIe-5413/5423 by increasing the number of points in the desired waveform which will help produce a smoother signal with faster slew rate.

The PXIe-54x3 devices support a maximum of 1024 steps in frequency list mode. This is significantly less than some previous arbitrary waveform generators due to limitations in the amount of on-device memory used to store frequency lists.

You can now change the digital gain on the fly on PXIe-54x3 devices. This means you can digitally scale a waveform while generating. The only exception is that you cannot change digital gain on the fly if the flatness correction property is enabled, as flatness correction requires digital correction coefficients to be pre-computed.

Script Mode is supported on the PXIe-5423 and PXIe-5433, but not the PXIe-5413. On the devices that do support script mode, break statements like if/else statements are not supported.

The PXIe-54x3 devices have standardized on using rising edge triggers. Because these devices only use rising edge triggers, properties like “Active Level” and “Marker Initial State” are no longer relevant and therefore not supported on these devices. In addition, the PXIe-54x3 devices have standardized marker and event pulse width to be fixed at 200 ns.