I just tried the following (using OpenThread emulation on posix):
# make -f examples/Makefile-posix REFERENCE_DEVICE=0 FULL_LOGS=1
# make -f src/posix/Makefile-posix REFERENCE_DEVICE=0 FULL_LOGS=1
# sudo wpantund -s 'system:./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp ./output/x86_64-unknown-linux-gnu/bin/ot-rcp 1'
And was able to see logs from both the RCP and NCP:
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [INFO]-MLE-----: Send Advertisement (ff02:0:0:0:0:0:0:1)
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [DEBG]-MAC-----: Request to start operation "TransmitDataDirect"
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [DEBG]-MAC-----: Starting operation "TransmitDataDirect"
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [DEBG]-MAC-----: RadioState: Receive -> CsmaBackoff
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [DEBG]-MAC-----: RadioState: CsmaBackoff -> Transmit
Sep 30 20:57:10 ad05e9417cbc ot-rcp[43495]: [1] [DEBG]-MAC-----: RadioState: Receive -> CsmaBackoff
Sep 30 20:57:10 ad05e9417cbc ot-rcp[43495]: [1] [DEBG]-MAC-----: RadioState: CsmaBackoff -> Transmit
Sep 30 20:57:10 ad05e9417cbc ot-rcp[43495]: [1] [DEBG]-MAC-----: RadioState: Transmit -> Receive
Sep 30 20:57:10 ad05e9417cbc ot-rcp[43495]: [1] [DEBG]-MAC-----: LinkRaw::TransmitDone(69 bytes), error:OK
Sep 30 20:57:10 ad05e9417cbc ot-rcp[43495]: [1] [DEBG]-MAC-----: LinkRaw::ReceiveDone(69 bytes), error:OK
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [INFO]-MAC-----: Frame rx failed, error:InvalidSourceAddress, len:69, seqnum:47, type:Data, src:166ecdd1631eae1d, dst:0xffff, sec:no, ackreq:no
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: [DEBG]-MAC-----: RadioState: Transmit -> Receive
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: ==============================[TX len=069]===============================
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: | 41 D8 2F 7B 5C FF FF 1D | AE 1E 63 D1 CD 6E 16 7F | AX/{\.....cQMn..
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: | 3B 01 F0 4D 4C 4D 4C 04 | 58 00 15 09 00 00 00 00 | ;.pMLML.X.......
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: | 00 00 01 02 CE C3 3F 10 | 9B 6F AB FD CB 6C 64 44 | ....NC?..o+}KldD
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: | B9 31 7C 07 37 9B 9F BA | 5C A7 86 22 94 D5 E4 0A | 91|.7..:\'.".Ud.
Sep 30 20:57:10 ad05e9417cbc ./output/posix/x86_64-unknown-linux-gnu/bin/ot-ncp[43493]: | 20 38 76 3C EC .. .. .. | .. .. .. .. .. .. .. .. | 8v<l...........
--
Jonathan Hui