Troubleshooting Wireless Recording Issues

First of all, a rundown on the different access point LED codes:

• Solid green: The access point is not receiving data from any monitors. This is the expected behavior when the monitors are all docked or powered off. If the LED on the access point is solid green when the monitors are configured for streaming, something is wrong either with your configuration or the hardware.

• Flashing only green: Everything is going well. The access point is getting data from all monitors and latency is low.

• Flashing only red: The access point is not getting any data from one or more monitors.

• Flashing green-red: The access point is getting data from all monitors, but latency is greater than 3s and increasing. Often caused by a monitor being partly obstructed or a bad wireless environment.

• Flashing green-blue: The access point is getting data from all monitors, but the latency is greater than 3s and decreasing. Often caused by a monitor being partly obstructed or a bad wireless environment.

• Flashing green-yellow: Access point is receiving data from one or more monitors that it is not expecting to receive data (e.g. there is a monitor configured on another computer system streaming data).

Error messages and associated troubleshooting

• If you encounter the “Access point could not be opened” error when starting a trial, please perform the following tasks until you are up and running again or you get to the bottom of the list:

• Note what the LED on the access point is doing. Note what the LEDs on the monitors are doing.

• Unplug the access point, wait a few seconds, and replug it in. Re-apply the configuration. Attempt to start the trial again.

• Unplug the access point, wait a few seconds, and replug it into a different USB port. Re-apply the configuration. Attempt to start the trial again.

• Redock all monitors and attempt a new configuration. Attempt to start the trial again (try it before putting all of the monitors on the subjects to see if you get past the error).

• Replace the access point USB cable with another one and create a new configuration.

• Whether you get up and running again or not, please upload your log files using these instructions.

• If you encounter the “Access point could not be read from” error when starting a trial, follow the steps from the previous issue (“Access point could not be opened”). This may indicate a faulty access point USB cable, as this message will be displayed if communication with the access point is terminated during the middle of a streaming session.

• If you encounter the “Could not synchronize data from all monitors” error or if your wireless connection is dropped mid-streaming session, first note the LED pattern on the access point and follow the instructions below:

• The access point is flashing green-red. This indicates that the access point is receiving data from all of the monitors, but there is interference of some type.

• One or more monitor is obstructed somehow. For example, a monitor may be worn with the lid facing inward, on the lumbar of a subject sitting in a metal chair, etc. Remove the obstruction to confirm that the access point is blinking green, or green-blue (as the data stream catches up) to indicate that data from all monitors is now being received.

• There is wireless interference. Try configuring on a different channel in the “Setup” tab.

• The radio on one or more monitors or the access point is marginal. If you still see the green-red pattern on the access point even when the monitors are all sitting right in front of the access point with clear line of sight, it is possible that one of the antennas in either a monitor or the access point is damaged. You can try two things to further troubleshoot this:

• Swap out the access point and USB cable and see if your issue is resolved.

• Configure the monitors one at a time (e.g., only select the lumbar site and cycle through each monitor). See if the problem is present for each individual monitor, all of the monitors, or none of the monitors. Note the ID of any problematic monitors and contact APDM support with your findings.

• The access point is flashing red (NOT yellow-red or green-red, just red). This means that the access point is not receiving data from all of the configured monitors. This may be true if:

• Not all of the monitors are undocked. If this is the case, undock all monitors and wait several seconds for the access point to blink green.

• One or more monitor has run out of battery. This will be evident if the LED on one or more monitors is not flashing at all.

• One or more monitor is obstructed somehow. For example, a monitor may be worn with the lid facing inward, on the lumbar of a subject sitting in a metal chair, etc. Remove the obstruction to confirm that the access point is blinking green, or green-blue (as the data stream catches up) to indicate that data from all monitors is now being received.

• The radio on one or more monitors is not broadcasting. If this is the case, it is useful to determine which monitor is having trouble so that we can track whether this is a hardware issue or not.

• If the problem is indeed the radio, than the monitor should not be receiving data from the access point either. This is reflected in a special LED code on the monitor -- where the monitor will typically flash green to indicate the battery level, the first of these flashes will be blue if it is not receiving data from the access point. Note the ID of any monitors that have this blue flash. If all of the monitors have this blue flash, the issue may be with the access point radio.

• If you do not see one or more monitors flashing blue, follow these instructions to determine the problematic monitor:

• After configuring, undock the first monitor from the docking station. Within 5-10 seconds, the access point should start blinking red. This blinking pattern indicates that the access point is receiving data from some, but not all of the monitors. In this case, it is getting data from the monitor you just undocked, but not the ones that are still docked (their radios don't turn on until they are undocked).

• If you see the access point blink red, the monitor you just undocked is transmitting to the access point. Redock it and move onto the next monitor, repeating the test.

• If the access point never starts blinking (and remains solid green) when you undock one of the monitors (with the rest all docked) then this is a problematic monitor. Note the ID of the monitor, dock it, and move onto the next monitor in case there are problems with more than one (not likely).

• After determining the issue and noting the IDs of the problematic monitors, you can try to recover in the following way:

• Plug the monitors back into their docking stations, and press the "Power Off" button in Motion Studio.

• Unplug the monitors and wait for them to power down.

• Next, place them back into their docking stations and wait for them to power up.

• Finally, unplug them from their docking stations (no re-configuration required) and wait for them to power up and start broadcasting. Often, this reset will enable the radios on the malfunctioning monitor.

• If this doesn’t work, try reflashing the default firmware on the problematic monitor(s). See the corresponding section in the “Common Troubleshooting Routines” for further instruction.

• You encounter excessive latency after successfully configuring your system and starting a streaming session -- even when the monitors have clean line of sight with the access point. This may be evidenced by having a system that is streaming efficiently after configuration (access point blinking green), but the access point starts blinking blue-green or red-green during the recording, indicating a data stream that is falling behind. The monitors may also blink blue-green, indicating that they are not receiving timing information from the access point.
• Note: This is expected behavior when the communication between the access point(s) and one or more monitors is at its limits. It may simply indicate that you are nearing the range of the monitors (all data will be buffered and not lost, but this is the source of the latent data). If this is the case, the system should return to normal when they get within range (the latency indicator in the recording dialog should begin to drop).
• The following scenarios are possible:
• One or more monitor is obstructed somehow. For example, a monitor may be worn with the lid facing inward, on the lumbar of a subject sitting in a metal chair, etc. Remove the obstruction to confirm that the access point is blinking green, or green-blue (as the data stream catches up) to indicate that data from all monitors is now being received.
• There is wireless interference. Try configuring on a different channel in the “Setup” tab. Get advice on how to choose a good channel here.
• The radio on one or more monitors or the access point is marginal. If you still see the green-red pattern on the access point even when the monitors are all sitting right in front of the access point with clear line of sight, it is possible that one of the antennas in either a monitor or the access point is damaged. Swap out the access point and/or USB cable and see if your issue is resolved.
• One or more monitors has run out of charge. If this is the case, the LED on the monitor (while still undocked) will no longer be blinking. Place it back in the docking station to start the charging process.
• To determine which monitor or monitors are having trouble communicating:
• Put the system into debug log mode (Help->Logging). This makes the log files more verbose, but also prints more information to the console. 
• If you are not using Motion Studio for recording, go into the Motion Studio view (View->"Motion Studio View") or open the console view in Mobility Lab (View->Console)
• Start a recording session by clicking on the "Stream" button. In the console, information will be printed whenever one of the monitors has to attempt multiple times to send a piece of information. If these re-attempts mostly come from one monitor, the radio in this monitor may be problematic. If the behavior seems to be fairly uniform among all of the monitors, then the access point may be problematic. In either case, create a support ticket describing this issue and, preferably, include some of the console output for reference.