A JACE has its own license file that is generated by Tridiums licensing portal at http://axlicensing.tridium.com. You can buy a license from any Tridium reseller. License limits include devices and/or points. So you can buy a JACE license with say 10 device limit and 500 points. The United States licensing model is slightly different than European, as it limits the number of devices as well. If you have a custom driver that extends BBasicDevice then each device added will soak up the device limits. When a station is started, it maintains a tally of the number of devices. This is why, when you keep deleting and adding again, you eventually will hit your limit. So the tally only goes one way, thats up, to prevent tampering, until you restart the station.
WorkPlace or Workbench Licensing
Niagara WorkPlace or Workbench, Tridiums commissioning and engineering tool also has its own license file and uses the host id to generate a license file. The host id is a unique number generated by the pc. It takes various bits from the machine hardware and operating system, e.g. hard drive serial number etc. This is why, when you apply Windows updates, you often change your host id. So you can't just swap hard drive or upgrade your operating system without relicensing.
The host id is then HTTP POST to http://axlicensing.tridium.com/ws/license/api31/getByHostId. A license is returned and saved on the operating system, workbench opens correctly, and off you go. Niagara also has a windows service, called the platform daemon which is the Platform management service for Niagara tools. This service will not start unless you have a properly licensed machine.
When developing drivers, at the top level you have a network, and a network has devices. If your custom driver extends BBasicDevice or any of its parent object, then it comes under the device limits.
The network has one method which checks the license. (See Image) If you're a developer partner, you have your own licensing portal. You can create licenses for your custom drivers to sell on and limit devices and points if needed. This is not to be confused with JACE license limits. That still applies unfortunately.
N4 Licensing Migration
Any platform converted from NiagaraAX to Niagara 4 requires a Niagara 4 license file, as existing AX licenses files are incompatible. Without an N4.0 license file, any N4.0 JACE controller or Supervisor is unable to run a station. An N4.0 engineering workstation without an N4.0 license file is also unable to run Niagara 4 Workbench.
Note that any JACE controller converted to N4.0 uses the same Niagara host ID as it did NiagaraAX. Reference this host ID when you request N4.0 licenses.
Typically any Supervisor PC or engineering workstation upgraded from AX-3.8 to N4.0 uses the identical Niagara host ID as well, providing its operating system remains unchanged. However, note that a Niagara 4 ( N4.0) license is not “backward compatible” with any NiagaraAX install.