Campbell Scientific OBS-Mobile Software for Archer-OBS - Manual (Page 22)

Section 2. Troubleshooting
4. The OBS-3A and the Archer are not set to the same baud rate or
communication protocol (e.g. RS-232, USB, RS-485).
• Check Serial Port Settings on the OBS-3A tab. The default baud
rate is 115.2 kb. If the Archer is not set to this speed, follow the steps
in Section 1.4 to set it.
• If the OBS-3A still fails to respond, try changing Archer baud rates
and clicking until communication is established (e.g. 57.6, 38.4,
19.6, 9.6 kb, etc.). If this fails, switch the Archer back to 115.2 kb
and go to the next step.
• Reconnect the cable and try
.
• Replace the main batteries; see Section 2.2 and try
.
• If you have a survey cable, connect instrument to external power and
try .
• Remove the unit from the pressure housing and press and release the
RESET button. Try .
Power failed due to battery clip corrosion or a broken power wire.
Check for a broken red wire connecting the battery tube and circuit board.
Green powder or tarnish on the battery contact parts indicates salt-water
corrosion. Remove the electronics from the pressure housing. Pull battery-
clip-retainer pin out with needle-nose pliers and slide the clip from its track.
Clean the corroded surfaces of clip and track with a Scotch-brite
® pad and
reassemble unit.
OBS or other sensor malfunction.
• Inspect for physical damage such as a broken or bent thermistor, a dirty
conductivity sensor, or an OBS sensor fouled with marine growth.
• Open unit and inspect for broken sensor and communication wires and
loose connectors (FIGURE 2-1).
• Check sensor power by starting Survey mode
and selecting all
sensors. Green LEDs should illuminate for installed sensor.
• If the depth sensor reads high and does not change, it may need to be
cleaned (see pressure-sensor maintenance, Section 5.2).
• If the sensors appear to be in working order, the digitizer or
microcontroller may be damaged. Such problems usually require factory
service.
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