After enabling Read Protection on your EM35x chip, you may notice that capture with InSight Desktop (ISD) doesn't seem to work properly.  This is expected behavior... While the PTI pins don't strictly rely on the SerialWire/JTAG (SWJ) interface (which is locked out by the Read Protect mechanism), the ISA3 firmware wants to continually strobe the SWJ port looking for Virtual UART activity to pass up to ISD, so this periodic poking of the SWJ pins causes the read protection circuitry to latch in the CPU core, essentially halting the chip from further execution until next reset.

To work around this nuance, the newer builds of ISD (see 2.5.26, available through auto-update or through the portal in the Development Tools section) include a new checkbox in the "Start Capture With Options" menu selection (from the Adapters context menu accessible by right-clicking on your target ISA3) called "Turn debugging off".  This will stop the ISA3 firmware from strobing the SWJ port when you connect with ISD, so you should be able to get PacketTrace events from the node even though other debug functionality like Virtual UART, API Tracing, single-stepping/breakpoints, and other non-Packet events in ISD will be disabled (as those require SWJ activity).  

If you still see a problem when doing Start Capture With Options and enabling "Turn debugging off", please contact Ember Support for further assistance.