© Copyright 2000 National Instruments. All rights reserved.
Thank you for using National Instruments NI-DAQ for PC Compatibles, version 6.9, for Windows 2000/NT/Me/98/95.
This file contains important information regarding this version of NI-DAQ. Please read it carefully so that you will be aware of any known problems or incompatibilities.
Information in this file is organized in the following sections:
Some of the products listed below are not currently released, but all of the following new products are supported in NI-DAQ 6.9:
This is a list of products not supported by NI-DAQ 6.5 or later, and the latest release of NI-DAQ that supports them:
To use any of these products, you must use the NI-DAQ version listed in parentheses or an earlier version.
Starting with NI-DAQ 6.7 for Windows, the NI-DAQ Setup Utility no longer has an option to install LabVIEW for Windows version 4.x Data Acquisition support files (English and Japanese).
If for any reason you need to re-install LabVIEW for Windows version 4.x Data Acquisition support files, and you require the use of the NI-DAQ for Windows version 6.7 driver, you can install the core driver components and LabVIEW 4.x DAQ support from an older version of NI-DAQ for Windows (recommended: NI-DAQ 6.6 for English, NI-DAQ 6.1 for Japanese), then install the NI-DAQ for Windows version 6.7 core driver components on top.
As of NI-DAQ 6.7 and later, the LabVIEW for Windows Data Acquisition Library LLBs in the following list (installed in <LabVIEW>\vi.lib\daq) now contain function calls to a dynamic link library (DLL) called LVDAQ.DLL. (This DLL is located in the same directory as the LLBs and replaces the code interface nodes (CINs) that were previously embedded in each VI.)
These LLBs and the DLL are compatible with LabVIEW for Windows 5.x, LabVIEW RT version 5.1.2 or later, BridgeVIEW 2.x, as well as LabVIEW Student Edition version 5.x for Windows. These LLBs are backwards compatible, that is, they will load without a broken Run button, with NI-DAQ for Windows version 5.0 or later. If a particular operation or feature is not supported, some VIs return DAQ error code –10242 (functionNotFoundError) when you run them.
One benefit of changing the VIs to call DLL functions instead of CINs is that VI load time is drastically improved. Our benchmarks, run on a Pentium III-500 MHz Dell Precision 610 running Windows NT 4.0 SP4, have shown at least a 75% reduction in load time, on average, after the NIDAQ32.DLL is loaded into memory when the first DAQ VI is loaded in LabVIEW.
The following LabVIEW related files are no longer needed with LabVIEW for Windows when used with the Data Acquisition LLBs installed with NI-DAQ 6.7 or later:
NOTE: If you are using LabVIEW Application Builder to create an executable that calls DAQ Library VIs, you may manually need to add a reference to LVDAQ.DLL in your build script.
Following are lists of LabVIEW Data Acquisition examples new in NI-DAQ 6.9 grouped by the default installation locations of the files.
The following examples are added to the vi.lib folder:
The following examples are added to the examples folder:
The following NI-DAQ C API examples written in Visual Basic, Visual C++, CVI, or Borland C++ are added to <Examples Directory>\daq\CDIO\:
If you are using LabVIEW 5.1.2 with an RT Series PXI Controller, NI-DAQ 6.9 will detect the Remote System Explorer if it is installed on your system and automatically update the data acquisition files. After the NI-DAQ installation completes, follow these instructions to update the PXI controller:
DSA devices do not support analog input/output non-buffered operations. In LabVIEW, AI SingleScan and AO Single Update VIs are not supported.
If you have already installed a version of the DSA instrument driver, you must install its latest version to work with NI-DAQ 6.9.
As of NI-DAQ 6.7 and later, software support for USB and 1394 is provided only for Windows 2000, Me, and 98 single processor systems. If you are running another version of Windows, you will need to upgrade your operating system to use USB or 1394 devices.
NI-DAQ version 6.5 or later is required to use USB DAQ devices.
NI-DAQ version 6.6 or later is required to use 1394 DAQ devices.
LabVIEW version 4.0 or later is required in order to use USB or 1394.
It is best to connect your USB or 1394 DAQPad to your PC and power it on before launching your DAQ application or Measurement & Automation Explorer. If you connect or power on your DAQPad after your DAQ application is loaded, reset the device in software before attempting to use it by running Device Reset.vi (in LabVIEW) or calling Init_DA_Brds() in the NI-DAQ API.
If you are using a DAQ application that does not support manual resets, like VirtualBench, you must connect and power on your USB or 1394 DAQPad before running your application.
On rare occasions, USB or 1394 devices will not appear in the Measurement & Automation Explorer device tree if any Windows Explorer (including Internet Explorer) windows are open. If this problem occurs, close all Explorer windows and refresh the Measurement & Automation window by pressing <F5>. If the problem still occurs, restart the system.
USB and 1394 DAQPads do not support Windows Me/98 suspend mode.
USB and 1394 devices support plug-and-play configuration and hot swapping, and Windows Me/98 provide some operating system support for power management. Although these features generally facilitate device configuration, please follow the guidelines in this section to avoid configuration problems.
Under certain conditions, problems may occur when simultaneously disconnecting multiple 1394 devices during data acquisition. It is very important that you connect or disconnect devices before loading any data acquisition software.
After disconnecting or turning off a device, you should wait 5-10 seconds (or until the hourglass icon goes away) before turning the device back on.
On some computers, power management can interfere with active DAQ applications that are using USB or 1394 devices. If your DAQ application needs to run while the computer is unattended, disable the power management features in the operating system and the BIOS, as well as your screen saver.
To disable power management in Windows Me/98, do the following:
To find out if your system has power management built into the BIOS, and for instructions to disable BIOS power management features, refer to your system documentation.
To disable your screen saver, do the following:
USB/1394 performance depends highly on system-specific factors such as CPU speed, memory architecture, and system chipset characteristics. USB and 1394 operations are software-intensive, so running other applications during data acquisition operations may affect performance. Higher-speed USB and 1394 operations may also affect the performance of other applications.
All the USB and 1394 devices connected to your PC share the same bandwidth. Using multiple USB and 1394 devices simultaneously may affect the performance of DAQ applications. Also, since the PC's USB and 1394 host controllers reside on the PCI bus, using other bandwidth-intensive PCI devices may affect performance.
Because data is transferred across the USB and 1394 buses in packets, the timing of operations involving the transfer of small or precise amounts of data is less deterministic than with plug-in DAQ devices. For example, the timing of messaging and interrupt-intensive operations is likely to vary more with USB and 1394 devices.
Externally-timed A/D: By default, the DAQPad-6020E supports external sample-interval and scan-interval timing for low speeds (up to about 90 Hz). For faster external sampling, run Set DAQ Device Information VI (or equivalent) with Information Type = interrupt generation mode and Information Setting = generate interrupt every half FIFO.
Software analog triggering: The DAQPad-6020E supports software analog triggering only for low-speed acquisitions (up to about 75 samples/sec). This restriction does not apply to other types of triggering. For more information on analog triggering, refer to the Config_DAQ_Event_Message topic in the NI-DAQ Function Reference Help, or the AI Trigger Config VI in the LabVIEW DAQ Help.
Continuous, low-speed AI transfers: With the DAQPad-6020E, at the beginning of a continuous, low-speed AI transfer (from 80 to about 400 samples/sec), there is a noticeable delay before data begins to arrive in the acquisition buffer. The reason is that, although A/D conversions are being generated, the device will not begin transferring data to the PC until its AI FIFO becomes at least half full.
Timed non-buffered AI: On the DAQPad-6020E, timed non-buffered AI operations, as illustrated in the LabVIEW example Cont Acq&Chart (hw timed) VI, are limited to about 50 Hz. At higher rates, LabVIEW may become unresponsive as NI-DAQ tries to empty the AI FIFO by reading one scan at a time from the device.
We have noted that some 1394 adapter boards report incorrect FIFO sizes. Therefore, we use the lowest common denominator for the FIFO size. If your 1394 adapter board has a FIFO depth greater than 456 bytes or reports the wrong speed, you should download fwctl.exe and readme.txt from ftp://ftp.natinst.com/support/daq/pc/ieee1394 in order to increase performance.
Typically, one may disable board and mini-MITE FIFOs within control applications in order to remove sluggishness. However, this action impacts all DMA channel transfers on the DAQPad-6070E. Also, you can only change FIFO sizes before running any DMA transfers.
Performing a scan before running an internal calibration using SCXI_Calibrate could result in a –10636 error (You cannot start a continuous (double-buffered) operation with a synchronous function call). If developing in C, call the DAQ_DB_Config function with the device number of the DAQ device you are using to calibrate and Dbmode = 0. If you are using LabVIEW, run the Device Reset VI on the DAQ device. You can also exit your development environment and start up again.
When a 6527 device is using an interrupt level (IRQL) that matches the IRQL of either a USB Host Controller or a 1394 Host Controller, change detection may not work. Refer to the Interrupt Performance Issues between PCI Devices and Windows 98 section for more information on this issue and ways to work around it.
Improved buffered output operations: The 6534 devices feature two memory modules onboard, one for each group. By default, NI DAQ will pre-load the SCARABs with either the entire data buffer or the entire memory module, whichever is smaller, before starting the output operation, thus eliminating the bus bandwidth limitations. However, you may override the default pre-loading by running DIO Parameter VI (in LabVIEW) with Parameter name = SCARABs Preload Enable and Value in = Off.
If you are programming in C, call Set_DAQ_Device_Info (NI-DAQ API) with infoType = ND_FIFO_TRANSFER_COUNT and infoValue = ND_NONE.
Continuous, high-speed output with repeat data: The 6534 devices support output memory looping mode in which the output data are loaded into the SCARAB only once, and the entire buffer is repeated over and over again, provided that the buffer size is less than or equal to the onboard memory size. To do so, run DIO Parameter VI with Parameter Name set to Pattern Generation Loop Enable, then do your normal DIO configuration for continuous output operation with regeneration mode enabled. If you are programming in C, call Set_DAQ_Device_Info with infoType = ND_PATTERN_GENERATION_LOOP_ENABLE and infoValue = ND_ON.
Onboard memory size: The 6534 devices feature memory modules of various sizes. To query the memory size of your 6534 device, run Get DAQ Device Information VI (in LabVIEW) with Information type = SCARAB A Memory Size (for group 1) or Scarab B Memory Size (for group 2). If using another development environment, call Get_DAQ_Device_Info (in NI-DAQ API) with info Type = ND_SCARAB_A_MEMORY_SIZE (for group 1) or ND_SCARAB_B_MEMORY_SIZE (for group 2). The memory size is returned in bytes.
20 MHz pattern I/O: You can set the clock frequency to 20 MHz by running Digital Clock Config VI or DIO Config VI. If you are programming in C, call DIG_Block_PG_Config with timebase = –3 and interval = 1.
Interrupt processing may be slower on systems that exactly match all of the following conditions:
Extreme sluggishness, timeouts, or lockups may occur on systems that exactly match all of the following conditions:
To determine if the IRQL of your PCI DAQ device and USB/1394 Host Controller are the same, follow these instructions:
If the setting number of the PCI data acquisition device matches the USB/1394 host controller, you improve interrupt processing performance by following the instructions below.
NOTE: The sharing of an IRQL between the USB/1394 host controller and the PCI data acquisition device affects only the speed of processing interrupt transactions. It does not affect DMA or other I/O. Also, the sharing of an IRQL between any number of PCI data acquisition devices or other PCI devices, such as a video or network adapter, should not affect the interrupt processing speed.
If you are not using a USB/1394 device, and don't plan on using one for some time, do the following:
USB:
1394:
If you are using or plan to use a USB/1394 device, the following instructions might work:
If you are not using a USB/1394 device, and don't plan on using one for the time, you can do the following:
Note that some devices cannot be disabled via the BIOS settings. In this case, try to disable the device(s) via the device manager within Windows.
If the methods described above do not work, you can try following these instructions.
NOTE: This method should be used only as a last resort, since it requires you to manually change computer resources.
USB:
1394:
If you plan to use an SCXI-1104 or SCXI-1125 with a Remote SCXI configuration, you must update the firmware on your SCXI-2000 chassis or SCXI-2400 module. If you have Remote SCXI and do not plan to use an SCXI-1104 or SCXI-1125, no update is necessary.
To perform the firmware update:
If you want to use NI-DAQ 6.9 in an RDA application, be sure to run NI-DAQ 6.9 on both your client (local) and RDA server (remote) computers. This requirement is due to the new RDA security features added for this version.
The security features allow you to specify a password for each device configured on the server, in order to restrict RDA to that device to clients who know the correct password. To set the password for a device, follow these instructions:
After you set a password for the device, RDA clients must specify the correct password in order to use the device through RDA. By default, the password is empty, indicating that the device is not password-protected. If a client is already using an RDA device when the password is changed, the client will get a –10340 error until they set the correct password. To set the correct password, follow these instructions:
In addition to each device-level password that can be set on the server, there is a root-level password that can be set to prevent unauthorized users from remotely configuring the RDA server. To set this password on the server computer, open Measurement & Automation Explorer on the server and select Tools»NI-DAQ Configuration»Set Remote Configuration Password. After you set this password, clients attempting to remotely configure the server through Measurement & Automation Explorer (by clicking Tools»NI-DAQ Configuration»Remote DAQ Configuration) will have to enter the correct password first. Clients that know the correct root-level password have the ability to change the root-level password of the server as well as each of the device-level passwords through Remote DAQ Configuration.
Another feature added to RDA for NI-DAQ 6.9 is the ability to view, create, edit, and test named channels for RDA devices in Measurement & Automation Explorer (MAX). When you configure an RDA device, you can see the named channels of that device in the Data Neighborhood folder, along with the channels connected to local devices. The icons of the RDA channels will differ slightly from those of the local channels so you can tell them apart. Through MAX, you can create or edit the RDA channels as you would local channels. However, when you do this you actually are modifying the configuration of the server itself, because the RDA channel information is stored exclusively on the server.
For NI-DAQ 6.7 and later, RDA has the ability to time out. This is useful when your network connection is lost while your RDA client computer is waiting to receive a response from your RDA server computer. Without the timeout, your RDA client computer will wait forever, causing your LabVIEW program to appear to hang. With the timeout feature, your LabVIEW program will return the -10340 noConnectError instead.
The default value for this timeout is 240000 milliseconds (4 minutes). To change this, you must add a value to an existing registry key. Follow these steps to do so:
Be aware that NI-DAQ calls that read or write data can take a long time to return depending on your rates and the amount of data. Calling AI Buffer Read VI and reading 100 scans when you are acquiring at 10 scans/sec will take 10 seconds. If your ReceiveTimeoutValue is less then 10000 milliseconds, you will receive the –10340 error even though your network connection is fine.
National Instruments is no longer creating a Function Reference Manual for NI-DAQ. All of the NI-DAQ functions are now described only in the NI-DAQ Function Reference Online Help file. To view the NI-DAQ Function Reference Online Help, click Start»Programs»National Instruments»NI-DAQ»NI-DAQ Help.