Why Do I Get a Measurement & Automation Explorer (MAX) Database Connection Error?
Primary Software: Utility Software>>Measurement & Automation Explorer
Primary Software Version: 4.5
Primary Software Fixed Version: N/A
Secondary Software: N/A
Problem: I get a "MAX Database Connection Error" when I start MAX or when I try to view my devices and software. What should I do?
Solution: This error can result from a variety of causes which are listed below.
- Firewall Settings
MAX is divided into a front-end GUI (nimax.exe) and a back-end database service (nimxs.exe). This error is related to the method by which these front and back ends communicate with each other. MAX 4.1 performed this communication through TCP sockets. In previous and later versions of MAX, this communication was and is performed through shared memory. Additional NI services may still be using TCP for communication, so firewalls can still be the cause of this issue.
Because of this TCP communication, many firewall and internet security programs, such as McAfee Personal Firewall and Symantec Client Firewall, put MAX into a blocked programs list, which prevents it from establishing a connection to its database. In general, disabling the firewall will still leave MAX blocked from communication.
Removing MAX and all other NI applications from the blocked programs list is necessary for proper functionality. Some commonly blocked NI programs are: NIMax.exe, nimxs.exe, NiAsstnt.exe, nipalsm.exe, nidevmon.exe. This simple solution should be one of the first options explored when a database connection issue is seen in MAX - prior to uninstalling NI software.
NOD32 Anti-virus software could be blocking the HTTP port that MAX uses for the database. Please see the KnowledgeBase linked in the Related Links section if you have NOD32.
- NI Configuration Manager or NI Device Loader (nidevldu) Services Not Started
To verify if the NI Configuration Manager service is started and operating, go to Control Panel » Administrative Tools » Services. Scroll down to NI Configuration Manager (may show up as nidevldu). You may also launch Services by navigating to Start » Run and entering services.msc.
Update: If the NI Configuration Manager service does not appear in the list or has problems starting, the first thing to try is a Repair of MAX. Renaming/deleting the Data folder or un-installing and re-installing software is often unnecessary. To Repair MAX, go to Control Panel » Add or Remove Programs, find National Instruments Software in the list, and click Change/Remove. Find NI Measurement & Automation Explorer in the list, and click Repair.
Make sure the service's Status is started. If it is not, right-click it and select Start. Also, try restarting the NI Device Loader service. For these changes to take effect, close out of Administrative Tools, and restart MAX. If the NI Configuration Manager or nidevldu service was not started before, MAX should now be able to operate correctly.
- Disconnected ENET Device
If you previously had configured a Serial or GPIB-ENET device but this device is no longer connected, the server may experience some delays due to the timeout that occurs while trying to connect to the non-existent device(s).Due to the delay, MAX may report a Database Connection error. In this case, reconnecting the ENET device to the system or removing the reference to the ENET device will resolve this error. When switching between a Macintosh to a PC, you will need to reset the device to have it accessible.
- Database Corruption (Rare)
This error can also be seen due to a MAX database corruption. Please see the following KnowledgeBase article: KnowledgeBase 3L9AKO6E: How Do I Clean Corrupted MAX Database and Start With a New One?.
- PCI-7041 Driver Combination (Very Rare)
If you have the following combination of software installed, please see the KnowledgeBase in the Related Links section.
- NI-VISA 4.x
- PXI Platform Services 2.3
- PCI-7041 RT Plug-In Board driver (Nov 2005 and earlier Driver CD)
- NI-VXI
- Traditional NI-DAQ (Legacy) 7.x
If you continue to experience database connection error, please contact
NI Technical Support for further assistance.
Related Links: KnowledgeBase 48THDAQA: Why Do I Get "MAX Database Connection Error" When Using NOD32 Anti-Virus Software?KnowledgeBase 47DB3PA0: PCI-7041 (RT Plug-In Board) Driver May Hang System if Combination of Drivers is InstalledKnowledgeBase 4BHID6DE: NI Device Loader (nidevldu) and NI Configuration Manager Services Not StartingNI Technical Support
Attachments: 
- max database error.bmp
- services.JPG
Report Date: 10/18/2006
Last Updated: 04/24/2009
Document ID: 42HG08DD
- max database error.bmp
- services.JPG
