System shell

Any QNX-based JACE has a “system shell,” providing low-level access to a few basic platform settings. Using a special power-up mode and a serial connection via a USB-to-MicroUSB cable connected to the JACE’s Debug port, you can access this system shell. Note that system shell is also available via SSH (providing that SSH is enabled in the JACE).
 
NOTE: Starting in Niagara 4.2, the JACE-8000 can be converted (downgraded) to run AX-3.8U1–with some feature limitations. For example, for any JACE-8000 running AX the USB functionality is not supported. In this configuration the USB port on the device is not monitored for insertion/removal of devices.
 

Typical usage is for troubleshooting. However, in the case of IP address mis-configuration, you can use the serial system shell in order to regain access to the unit.

 
NOTE: Also, depending on your preference, you may wish to use the serial shell to set the JACE’s IP address, as an alternative to reconfiguring your PC’s IP address in Windows (to initially connect to a new JACE). If done as the first step, afterwards you could connect normally (Ethernet/IP) and perform all other Niagara software installation/platform configuration using Workbench and the Commissioning Wizard. This method would save you from having to re-configure your PC’s IP address settings in Windows: first to connect to the JACE as shipped from the factory, and then back again to its original settings.
 

The following sections provide more details.