Issue
Attempting to commission a controller in an LNS environment results in the following error:
Cannot communicate with the device. (Subsystem: NS, #26)
Environment
LonMaker, NL220
Cause
An NS, #26 error indicates a complete failure to communicate. Most often this will be the result of physical layer problems. In some situations it maybe due to a failed controller.
Resolution
Check the obvious physical layer connections:
- Is the cable plugged into the laptop to connect to FT-10?
- Is the router between the computer and device being commissioned online and communicating?
- Are the wires terminated properly at the controller?
- Is the controller powered?
- Are there end of line terminators fitted?
Inspect the controller:
- Are the LEDs blinking as designed?
- Are you able to receive a service pin from the device?
- Does an MOT or NXE need to be reloaded to the device?
Typical troubleshooting techniques will usually resolve an NS, #26 error once it is understood to be a complete lack of communication at the physical layer.