The article below is for advanced users ONLY.
New users to NCE / USB / JMRI should always start here: https://ncedcc.zendesk.com/hc/en-us/articles/200590919-Read-me-First-USB-Driver-Download-and-Installation-Instructions-
The V7 USB adapter defaults to Cab Address 3. However the cab address becomes user definable via the PC interface. This takes full advantage of the V1.65 software in the PowerCab/SB3a/SB5 system which allows you to move the NCE adapter into the "special accessory cab address range" and out of the usable Cab address range. In other words unlike the V6 USB software, you no longer have to give up a throttle/cab address to use the V7 NCE USB adapter. One of the USB Jumper Setting purposes is to LIMIT the type of commands that the USB adapter will pass on to the command station. For example, passing a programming track command to a SB3 system is not good idea since the SB3 does not support a Programming Track.
VERSION 7 JUMPER SETTINGS, SOFTWARE VERSIONS & LIMITATIONS
The following is a table of the functions that can be accessed or controlled by the computer with this version of the USB adapter.
1) DCC System Name: The name of the NCE system being used with the USB adapter.
2) DCC System Software Version: This is the version of software installed in the DCC system.
3) Jumpers: JP2, JP3, JP4 are the jumpers you must set on the USB board to match the DCC system Name.
4) Baud Rate: NCE USB uses RS-232 buad rate protocol. This is the speed of the USB adapter when set to this jumper configuration. 9600 is slower than 19200.
5) USB Cab Address: This is the cab address the USB adapter takes when connected to the Cab Bus of the DCC System. The cab address must not be shared with a throttle or any other cab bus device. If the cab address is not forced to 3 by jumper settings, then the PC software can program the USB cab address.
6) Accessory Address Range: The allowable address range for any DCC compatible accessory decoder device. For NCE, accessory decoder are the Switch-It or the Switch-8. To learn more, go here: Accessory Decoders
7) Accessory Ops Mode Program: Ops Mode programming for Accessories
8) Locomotive Ops Mode Program: Ops Mode programming for Locomotives. AKA Programming On the Main (POM)
9) AIU: Auxilary Input Unit. This is NCE layout feedback device that connect to the command station via the Cab bus and read by a PC running a program such a JMRI. Feedback is typically in the form of MONITORING signals from an Occupancy Detection device NCE Block Detector(s), Supervisory/Monitory Device (DCC Circuit Breaker) or spare contacts on a Turnout Motor (Tortoise).
10) CS Memory Access: Allow the computer to access Command Station memory to read status or control functions supported by the system.
Like the V6 of the USB adapater, the V7 USB interface can run trains, run macros and control signals on all NCE DCC systems.
Below is the matrix of things V7 does NOT support relative to the NCE system used.
 = DCC "Twin" is based on the PowerCab software.
 = There is no functional difference between a SB3 and a SB3a. The big difference is in the booster current rating which has nothing to do with the USB interface.
 = Any version of the 2007 system PROM/ROM/EPROM will work.
 = "All Systems" is the same as no limitations. No features will be restricted that are supported by the NCE V7 USB Adapter. One could use the "ALLSYS" setting for everything but NCE would not be responsible for what works or does not work. This includes the possibility of crashing the command station receiving the command it does not understand or who's value is beyond what it can support..
= Requires USB to RS232 adapter.
= There is no difference in command and control functions between a SB3 and a SB3a. NCE introduced a replacement version of the SB3a in a new package and calls it a SB5 which also includes a power supply.
= It has not been verified, but the only difference between this jumper setting and the other with this same note appears to be the accessory address range. V1.28C was never advertized as supporting more than 250 accessory decoders.