LabVIEW Real-Time Module 8.5.1 Readme

August 2007

This file contains important information about the LabVIEW 8.5.1 Real-Time Module.

Installation

You must install LabVIEW 8.5.1 before you install the LabVIEW Real-Time Module 8.5.1.

Refer to the LabVIEW Real-Time Module Release and Upgrade Notes for more information about upgrade and compatibility issues, a list of new features, and installation instructions. The LabVIEW Real-Time Module Release and Upgrade Notes is included as a printed booklet with the kit. You also can access the LabVIEW Real-Time Module Release and Upgrade Notes by selecting Help»Search the LabVIEW Help in LabVIEW and navigating to the Real-Time Module»Real-Time Module Related Documentation topic on the Contents tab.

Supported Platforms

The LabVIEW Real-Time Module supports Windows 2000/XP and Windows Vista (32-bit and 64-bit). The LabVIEW Real-Time Module does not support Windows NT/Me/9x.

New Features

The LabVIEW 8.5.1 Real-Time Module includes the following new features:

• Reliance filesystem support—The reliance filesystem provides fast disk access and data preservation in the event of a power interruption. Refer to the Using Desktop PCs as RT Targets with the LabVIEW Real-Time Module document for information about installing the Reliance filesystem on an RT Desktop PC target.
• Formatting RT Desktop PCs from Safe Mode—With previous versions of the LabVIEW Real-Time Module, choosing the format option from Safe Mode formatted only the RT partition of the hard drive. When version 8.5.1 of the Real-Time Module is installed on the target, the Safe Mode format option formats the entire hard drive.
• New supported targets—The LabVIEW 8.5.1 Real-Time Module supports the following new targets: CompactFieldPoint 2200, CompactRIO 9072 and 9074, PXI 8104, and the NI 1722 and 1742 smart cameras.
• Support for nVidia ethernet drivers—The LabVIEW 8.5.1 Real-Time Module includes support for all nVidia ethernet chipsets, which you can use with RT Desktop PC targets.

Known Issues

The Real-Time Module 8.5.1 includes the following known issues at the time of release.

All Target Platforms

• File I/O reads and writes of a drive formatted with the Reliance file system can slow down significantly when you include a large number of files in a single directory. Performance varies from system to system, but generally the slowdown appears when you include 1000 or more files in a directory. To avoid this issue, distribute files across multiple directories.
• If you format an RT target with an 8.5 format disk or Utility USB drive, you might not be able to downgrade the target to a previous version of the Real-Time Module. To downgrade a target from the LabVIEW 8.5 Real-Time Module to a previous version of the Real-Time Module, reformat the target with a format disk or utility USB drive created for a previous version of the Real-Time Module.
• When booting an RT Desktop PC target from a USB drive, certain BIOSes hang at the message "Waiting for USB to initialize..." To resolve this issue, remove the USB drive, wait a few seconds, and reinsert the USB drive.
• The Real-Time Module 8.5 introduced LogosXT, a new network protocol for shared variables, which can increase CPU usage in some cases. You can use an INI token to diable LogosXT and revert to the pre-8.5 Logos protocol. Refer to the National Instruments Web Site for more information about disabling LogosXT.
• If you modify and redeploy a VI, probes can stop receiving updates. After modifying a VI, you should close and recreate probes.
• If you format an RT target using a utility USB drive, you cannot subsequently format the target using a floppy drive.
• USB hard drives are not supported on RT targets. If you need to transfer files over USB, use a USB thumb drive.
• The disk footprint and the memory footprint of the Real-Time Module have increased by over 10% since version 8.2.1.
• When you create or add a VI under a specific target in the Project Explorer window, not all VIs and functions that appear on the palette are necessarily supported on that target.
• Indicators that are attached to local variables do not update properly through via remote front panel.
• Graphs and charts in subVIs do not display properly via remote front panel.
• The Strings[] property node does not supply a value until you make a remote front panel connection to the application.
• You cannot run LabVIEW Real-Time targets from secondary or removable hard drives.
• Queues allocated in RT VIs take up 150% of expected memory.
• Windows might fail to install or boot on a drive or partition formatted for LabVIEW RT. Before installing Windows on a drive or partition that has been configured or formatted for LabVIEW RT, delete the RT partition using a disk utility such as fdisk and recreate the partition for FAT32. While installing Windows, you can allow Windows to format the FAT32 partition.

ETS

• On RT PXI 8106 and 8196 targets, performing a TCP/IP write with a string larger than 64kB can consume CPU resources for several minutes.
• ETS targets can hang if a DHCP server forces an infinite lease time.
• Some USB thumb drives do not work on ETS targets. The following USB thumb drives are known to work properly on ETS targets: Memorex 1GB USB 2.0 TravelDrive, SanDisk Cruzer 128MB (non-U3), NexDisk USB 32MB (PSD-32N).
• ETS targets cannot use more than 2 GB of RAM.
• Desktop PCs that use processors without 64-bit writable RDTSC registers are not compatible with the NI RT Extensions for SMP. You can safely use an affected system as an RT target in single-core mode if you do not install the NI RT Extensions for SMP on the target. To use an RT Desktop PC as a multi-core RT target, the PC must use CPUs with 64-bit writable RDTSC registers.
• Desktop PCs that use AMD family 0Fh CPUs, distinguished by an integrated memory controller, typically ship with energy-saving features enabled in the BIOS. These energy-saving features can cause instability when the PC is used as an RT Desktop target with the NI RT Extensions for SMP installed. To use an affected PC as an RT Desktop PC target, you must either use the target in single-core mode or disable the energy-saving features in the BIOS. If the BIOS does not allow you to disable the energy saving features, you can safely use an affected system as an RT target in single-core mode by not installing or uninstalling the NI RT Extensions for SMP on the target.
• The maximum number of files you can open on an ETS RT target simultaneously is 256.
• If you receive an error while opening a TDMS file, closing the file can crash the RT target.

VxWorks

• Reading a shared variable that contains no data can cause slowdowns on VxWorks targets.
• VxWorks targets do not comply with the latest rules for Daylight Savings Time. As a result, VxWorks targets may report incorrect time from early March through early April and from late October through early November. The actual start and end dates of Daylight Savings Time differ from year to year, and not all regions participate in Daylight Savings Time. Refer to the official Daylight Savings Time regulations in your region for more information about the specific start and end dates of Daylight Savings Time each year.
  
  To prevent time fluctuations on the target, consider disabling Daylight Savings Time in the BIOS. If you need to compensate for Daylight Savings Time on the target, you can use the Set Date and Time VI to update the time at the beginning and end of Daylight Savings Time.
• The SMTP Email Send Message VI does not work on VxWorks targets.
• On VxWorks targets, using the Semaphore VIs and the Rendezvous VIs in the same application can cause errors and undefined behavior. You might also encounter errors if the application uses vi.lib\Platform\_goopsup.llb\GOOP Object Repository.vi in addition to the Semaphore VIs or the Rendezvous VIs.
• RT Ping.vi does not return the IP or MAC address on cRIO 9012 targets.
• On cRIO 901x targets, DNS lookup has a long timeout on private networks with no DNS server. If the network has no DNS server, there is no need to perform a DNS lookup.

Upgrade and Compatibility Issues

You might encounter the following compatibility issues when upgrading to the LabVIEW 8.5.1 Real-Time Module from a previous version.

Upgrading from 8.5 or Earlier

• On ETS RT targets, the timing behavior of the Wait (ms) function has changed. The Wait (ms) function uses the millisecond timer of the operating system to determine how long to wait. In the LabVIEW 8.2.1 Real-Time Module and earlier, the ETS RTOS counts the next tick of the millisecond timer as millisecond number 1 when counting the number of milliseconds to wait, so the actual amount of wait time is less than the amount you wire to the milliseconds to wait input, by no more than one millisecond. In the LabVIEW 8.5 Real-Time Module, the Wait (ms) function counts the next tick of the millisecond timer as millisecond number 0 when counting the number of milliseconds to wait, so the actual amount of wait time is more than the amount you wire to the milliseconds to wait input, by no more than one millisecond.
  
  If you have an application that relies on precise millisecond timing, test the application carefully to ensure the correct behavior. You might need to reduce the value of milliseconds to wait by 1 to maintain the same behavior as the LabVIEW Real-Time Module 8.2.1 and earlier. If you need wait resolution more precise than one millisecond, use the Wait Express VI on the Real-Time Timing VIs palette and configure the Counter Units to µSec.
  
  Note—The Real-Time Module 8.5.1 fixes an issue that arose due to the behavior change described above. Refer to bug ID 4D5CTEKI in the Bug Fixes section of this document for more information.
• Timed Loop error conditions that generated error −820 in the Real-Time Module 8.2.1 and earlier now generate error −818.

Upgrading from 8.2.1 or Earlier

• In Windows Vista, you cannot use the RT Disk Utilities in NI Measurement & Automation Explorer to create bootable floppy disks. However, if you have Administrator status in Vista, you can create a Desktop PC Utility USB drive by selecting Tools»RT Disk Utilities»Create Desktop PC Utility USB Drive in MAX.
• The Real-Time FIFO VIs have been replaced with the Real-Time FIFO Functions. These functions perform faster and contain additional functionality. For compatibility with upgrading applications, the previous Real-Time FIFO VIs still load from an existing LabVIEW block diagram, but they are no longer available on the Real-Time palette.
• When you install the Network Variable Engine on an RT target, you also must install the Variable Client Support with the same version number. When you upgrade a target from LabVIEW 8.0.x to LabVIEW 8.2.x, you also must upgrade the Network Variable Engine and the Variable Client Support. For the LabVIEW Real-Time Module 8.2.x, you must install Variable Client Support 1.2 and Network Variable Engine 1.2 on the RT target using the LabVIEW Real-Time Software Wizard in Measurement & Automation Explorer.
• The Real-Time Module 8.0 returns error code –2222 to indicate that a shared variable with the Enable Real-Time FIFO option selected has no value. The Real-Time Module 8.2 and later no longer returns error code –2222 but instead returns error code –1950679034 (0x8BBB0006) to indicate the same problem. This error code is consistent with shared variables that have the Real-Time FIFO disabled.
• You must enable the W2 hardware jumper to upgrade the RT Engine of an NI PXI-8145RT controller from version 7.1.1 and earlier to version 8.0 or 8.2.x. Refer to the PXI-8140RT Series User Manual for information about the settings and options for the onboard jumpers and switches.
• In the Real-Time Module 8.0, executables you build with LabVIEW and the Real-Time Module have a .rtexe extension, which is changed from the .exe extension in earlier versions. Although the extension change was cosmetic, in the Real-Time Module 8.2.x you might notice different behavior associated with the extension change. In the Real-Time Module 8.0 and earlier, you can run an executable built with LabVIEW and the Real-Time Module on Windows, and then use FTP to transfer the executable to an RT target and run it when you boot the RT target. In the Real-Time Module 8.2.x, you cannot run an RT executable (.rtexe) on Windows.
  
  If you want to run an RT executable on Windows and on the RT target, you must create and build two build specifications (one for Windows and one for an RT executable) and drag the necessary VIs for the build specification to each target in the project.
  
  Executables for VxWorks targets do not run on Windows or on Phar Lap ETS targets.
• The NI PCI-7041 is no longer supported with the Real-Time Module 8.2.x and later.
• The following USB thumb drive is not supported for RT target booting or storage: SanDisk Cruzer with U3 smart technology.
• If you read paths from a file or convert paths from strings and if you use different delimiters for file paths, the paths do not match in comparison operations even though the paths are functionally equivalent but with different delimiters. Review all paths and verify that all use the correct delimiter. Do not use UNC paths.
• Running the Execution Trace Toolkit on a VI containing Timed Loops might show incorrect thread names of Timed Loop threads if the trace is longer than a few seconds.

Bug Fixes

The Real-Time Module 8.5.1 includes the following bug fixes.

The Real-Time Module 8.5.1 also includes the following bug fixes, which became available in version 8.5.

Copyright

© 2005–2007 National Instruments Corporation. All rights reserved.

Under the copyright laws, this publication may not be reproduced or transmitted in any form, electronic or mechanical, including photocopying, recording, storing in an information retrieval system, or translating, in whole or in part, without the prior written consent of National Instruments Corporation.

Trademarks

National Instruments, NI, ni.com, LabVIEW, and LabVIEW Real-Time Module are trademarks of National Instruments Corporation. Refer to the Terms of Use section on ni.com/legal for more information about National Instruments trademarks.

Patents

For patents covering the National Instruments products, refer to the appropriate location: Help»Patents in your software, the patents.txt file on your CD, or ni.com/patents.