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Locked Nodes In Designer

Goals and Symptoms

Attempts to access a meter in ION Designer may result in the message "The node is locked by". The nodes is locked so that not more than one users can write to the meter concurrently. When users access Designer via Terminal services and incorrectly end their session the sessions can stay alive and the affected nodes remain locked. This may even be true even through server reboots.
If someone leaves their terminal services session without logging off (leaving session open) then the node remains locked. Terminal Services has keep-alive mechanism implemented that renews these connections even after reboot.

Causes and Fixes

For Windows 2000 Terminal Server
Use Registry Editor to add a DWORD value, KeepAliveEnable, with a positive numeric value of 1 (which represents 1 minute) to the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server

Open Terminal Services Configuration in Administrative Tools, double-click RDP-Tcp in the Connections folder and click the Sessions tab.
Click to select Override user settings and make sure that Disconnect from session is selected and then click OK.

To view the full knowledgebase article go to :;en-us;216783

Another approach is the following:


When setting up the Microsoft Terminal Server you should: from within Administrative Tools go into Terminal Server Configuration and-->right click the connection-->go to properties-->set session properties to end disconnected or stale sessions.


Original article#9384, SWKB-0477
Last Revised: 12 Nov 2008 by DRM

Applies To: ION Enterprise - all versions


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