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Document Type: Example Program
NI Supported: Yes
Publish Date: Sep 12, 2006

653x Bidirection Bust Mode I/O in DAQmx

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Filename: 653x_burst_mode.zip
Requirements: View

This example consists of two VIs: 653xWriter.vi and 653xLoopback.vi, each of which are designed to run on a 6534 or 6533 High Speed Digital I/O board (PCI or PXI form factor). The 653xWriter.vi writes data out on port 0 and reads data in on port 2. 653xLoopback.vi reads data in on port 0 and writes the same data back out on port2 (hence, the "loopback" name).

The intent of this example is to show how to perform biderectional burst mode on two computers at the same time. This digital communication is implemented using Burst Mode handshaking I/O in DAQmx. Each DAQmx write task "Exports" the PCLK, and each DAQmx read task "Imports" the PCLK used to transfer data. The ACK and REQ lines referred to in Traditional DAQ are now called "Ready for Transfer Event" and "Pause Trigger," respectively. The notes on the block diagrams reflect this change in nomenclature. There are two additional lines of "handshaking" within each VI to ensure that each task is started in the proper sequence. These handshaking lines are used only once when the VIs are first started and then ignored. (Note the First Call? primitives connected to case structures in each VI).

To set up communication between two 653x boards, run the 653xWriter.vi and 653xLoopback.vi both on one computer or one of each on two computers. Cable the 653x devices together using a SH68-68-D1 cable. Note that if you are connecting two computers (each with their own 653x board), you should first power on each machine and then cable them together to avoid any potential ground loops. Run the 653xWriter.vi first and then start the 653xLoopback.vi (note the explicit 3 second delay in the 653xWriter.vi to allow you time to run the 653xLoopback.vi) Extra digital I/O lines are used to ensure the proper order of execution between the two devices.

Requirements


Filename: 653x_burst_mode.zip

Software Requirements


Application Software: LabVIEW Base Development System 7.1
Language(s): LabVIEW

Hardware Requirements


Hardware Group: Digital I/O (DIO)
Hardware Model: PCI-6533, PXI-6534, PXI-6533, PCI-6534
Driver: NI-DAQmx 7.4

 
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This example program (this "program") was developed by a National Instruments ("NI") Applications Engineer. Although technical support of this program may be made available by National Instruments, this program may not be completely tested and verified, and NI does not guarantee its quality in any way or that NI will continue to support this program with each new revision of related products and drivers. THIS EXAMPLE PROGRAM IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND AND SUBJECT TO CERTAIN RESTRICTIONS AS MORE SPECIFICALLY SET FORTH IN NI.COM'S TERMS OF USE (http://ni.com/legal/termsofuse/unitedstates/us/).