User manual

back to “” to disable encrypon. Simply making a serial connecon to the node to reset the encrypon key will
not be sufficient, as serial communicaons as well as over-the-air communicaons are encrypted.
Recovering an Unresponsive Node
As with any programming language, there are going to be ways you can put your nodes into a state where they
do not respond. Seng a node to spend all of its me asleep, having an endless loop in a script, enabling
encrypon with a mistyped key, or turning off the radio and disconnecng the UARTs are all very effecve ways
to make your SNAP nodes unresponsive.
How to best recover an unresponsive node depends on the cause of the problem. If the problem is the result of
runaway code (sleeping, looping, disabling UARTS, or turning off the radio) and “Erase SNAPpy Image” from the
Node Info pane will not work because it requires communicaon with the node. In these cases, you can usually
use Portal’s “Erase SNAPpy Image...” feature from the Opons menu to regain access to your node. This Portal
feature interrupts the node before the script has a chance to start running – before it can put the node to sleep,
fall into its stuck loop, or otherwise make the node responsive.
In the case of a lost encrypon key or an unknown channel/network ID, or one of many other combinaons that
may arise, Portal’s “Factory Default NV Params...” feature, also from the Opons menu, resets the node back to
the state it was in when delivered. (If you have intenonally changed any parameters, such as node name,
channel, network ID, various meouts, etc., you will need to reset them once you have access to the node.)
Reconfiguring your node aer reseng the default NV parameters can be more involved than simply correcng
a script and reloading it, so if you are not sure why your node is unresponsive it may be best to try clearing its
SNAPpy image first.
If these fail to recover access to your node, the “big hammer” approach is to reload the node’s firmware, which
you can also do from Portal’s Opons menu. Note that if the NV parameters are mis-set, reloading the firmware
will not recover access to the node as it does not explicitly reset the parameters in the process. All three of these
opons require that you have a direct serial connecon to the node.
For more on the use of these funcons, refer to the Portal Reference Manual.
44 SNAP® Network Operang System