Hi,
nrf-command-line-tools-10.16.0-x64.exe
If calling NRFJPROG_read_connected_emu_snr(..) ,when more than one JLINK is connected to the computer, a selection window pops up:

After selecting one of the JLINKs the function returns and delivers the serial number of the selected JLINK.
nrf-command-line-tools-10.17.3-x64.exe
The sequence described above no longer works. There is no pop-up and the serial number of the JLINK connected most recently is returned by NRFJPROG_read_connected_emu_snr(..)
Since this change has not been listed in the change log i would consider it a BUG.
If NRFJPROG_read_connected_emu_snr(..) would return a list of all connected devices that would be an even better solution (from my point of view).
\Eric