LINcab/LINpiggy with External Supply Voltage
The following picture shows the pin assignment.
Pin 3: VB- (Electrically decoupled ground)
Pin 4: Pdis (Power disable)
Pin 7: LIN
Pin 9: VB+
Connecting Pdis (pin 4) with VB– (pin 3) of the D-SUB of the network interface disables the internal voltage supply of the LINcab/LINpiggy. This makes it possible to perform measurements on the LIN bus, even with an external supply below 12 V.
More information you find in the document Accessories for Network Interfaces.