PXI FAQ's

A. PXI is a modular instrumentation platform designed specifically for measurement and automation applications.

With PXI, you can select the modules you need to integrate into a single PXI system from multiple vendors. Communication between the modules uses familiar PC-based technologies such as the 132 MB/s PCI bus, allowing high performance communication that leverages widely available software. PXI also integrates timing and synchronization into the system, so that you can pass signals between instruments for high performance and accuracy, without additional cabling.

A. The PXI bus combines the high-speed PCI bus with timing and synchronization designed specifically for measurement and automation.

The PXI trigger bus consists of 8 shared trigger bus lines, a low-skew star trigger, and a common 10 MHz system reference clock. Using these synchronization features, you can easily pass trigger, clock, and other signals between PXI modules to make the accurate, high-performance measurements that you need.

A. No, PXI was developed in the 1997 in conjunction with a number of companies that form the PXISA alliance.

Click here to visit the PXISA alliance website.

A. Yes, all the PXI hardware offered comes with LabVIEW VI's, see below a link with further details on the LabVIEW Plug N Play drivers from Adlink that are supplied free with every data acquisition card.

Click here to visit ADLINK's website.

A. PXI supports two module form factors, 3U PXI and 6U PXI. The 3U module form factor defines two interface connectors.

J1 carries the signals required for the 32-bit PCI local bus. J2 carries the signals for implementing PXI electrical features including trigger bus, star trigger and 10MHz clock. On a 3U cPCI module J2 is usually missing, but if included it carries the signals for 64-bit PCI transfers.

The 6U module form factor also defines two interface connectors and in the future may carry one additional connector for expansion of the PXI Hardware Specification.

To summarise, the J2 is reserved for PXI synchronization feature, such as trigger bus, star trigger, 10MHz reference clock and other signals. So a cPCI board with only a J1 connector can be used in PXI system; however, it is unable to implement the PXI-specific features.

A. We can provide a solution with the PCI-8570 and PXI-8570, which are PCI-to-PXI extension cards that communicate between PCI and PXI systems.

A single PCI-8570 (or PXI-8570) can extend to 2 further PXI Chassis's, resulting in controlling 2 PXI/CompactPCI chassis with a single controller.

Click here to view the solution.

A. The data throughput is up to 528 MB/sec (64-bit, 66MHz). The latency is 1 µsec across 1 extension card.

A. PXI-2000 series has the ability of software auto-calibration. Users only need to execute the calibration utility and this card will be calibrated automatically.

The utility comes along with our driver. In Window2000/XP, users can execute Start>>Programs>>D2K-DASK>>DAQ-2000 calibration utility. In Linux, it is under sample folder.

A. Synchronizing Multiple Chassis With the ZT1000PXI GPS Star Card Synchronizing multiple chassis is easy in LabVIEW using the ZT1000PXI GPS Star Card with the included CVI driver! Here is what you need to synchronize two chassis:

1. One Star Card for each Chassis with the included CVI drivers
   
2. LabVIEW with the ZT1000PXI GPS CVI Instrument drivers imported
   (see our app note on importing CVI Instrument drivers into LabVIEW)
   
3. 1 ribbon cable for the Front Panel Trigger I/O on the Star Card
   
4. 2 SMB to SMB cables to connect the REF output to REF input and the Star Trigger output to Star Trigger input on both devices.
   

On the Master system, create a Sync_master.vi. The following are the LabVIEW SubVI's you will need to place, and their connections, to get started
(the VI's created in this app note are available online here):

1. Initialize - connect visa address constant for address of Star Card.
   
2. Normal Trigger Control - Set "Source and Direction Mask" to hex 33333333. This sets the trigger control up to direct triggers to the backplane and to the front panel so they can be used elsewhere.
   
3. Reference control - Set "Reference Source" to internal clock.
   
4. Star Trigger/Event 2 control - Set "Star Trigger Source" to Normal Trigger 0. Now setting Normal Trigger 0 puts a trigger signal on the Star Trigger output line. This means that when a trigger is sent on PXI TTL0 (Normal Trigger 0), it goes to the front panel, the PXI backplane, and to the Star Trigger output (also to be used elsewhere)
   
5. Normal Trigger Flag Control - use "Flag Mask" to set or clear triggers. Example, if you wanted to send triggers PXI TTL1, PXI TTL2, PXI TTL5 and a trigger on the Star Trigger output line, the flag mask should be set to binary 00100111 and since Star Trigger output is tied to PXI TTL0, it will go high.
   
6. Close.
   

The Master system (using Sync_master.vi just created) is now ready to begin synchronization of the slave system.
On the Slave system, create a Sync_slave.vi. The following are the LabVIEW SubVI's you will need to place, and their connections, to get started.

1. Initialize - connect visa address constant for address of Star Card
   
2. Reference control - set "Reference Clock" to external clock
   
3. Star Trigger/Event 2 control - set "Star Trigger Source" to external Star Trigger input. This allows the device to receive the Star Trigger signal
   
4. Normal Trigger Control - set "Source and Direction Mask" to Hex 22222222 to catch PXI TTLx triggers from the front panel and pass them to the PXI bus or Hex 66666666 to catch the star trigger from the front panel and pass it to the PXI bus. (You can use combinations of 6s and 2s to get the desired triggers. Use Hex 62222226 to pass the Star Trigger to PXI TTL0,7 and to pass the PXI TTL1 - PXI TTL6 triggers to the backplane PXI TTL1 - PXI TTL6)
   Your chassis are now ready to be synchronized. You can use any combination of triggers to synchronize the instruments in one chassis to the instruments in the other by simply changing the Source and Direction masks appropriately). Or simply use the high quality reference clock to keep both chassis on the same time base