Transmitting a Test Message
When both modems are online and connected to their pshells, you can send an acoustic ping from one modem to the other to verify communication.
At the pshell prompt, enter:
ping 4
This command initiates transmission of a test packet using transmit-power setting 4 on the software scale. Popoto transmit-power settings use a 1 to 100 scale. Setting 4 is a lower transmit-power setting suitable for many air tests with the units' transducers spaced 1-2 meters apart.
During transmission, the transmitter indicates that it is actively sending. On OEM board-level systems this may be visible as the red transmit LED on the analog board. On enclosed and Deckbox systems, use the pshell output to confirm transmit and receive activity. The receiver's pshell should indicate that it received a packet and display both the packet and header data.
If the receiving modem reports a CRC error instead of a successful CRC check, room multipath may be preventing the demodulator from decoding the test packet. Reposition the transducers or pad reflective surfaces to reduce acoustic reflections.