Timekeeping

Why are my logged recordings all from January, 1970? or Why is the time displayed on my Opal from 1970?

When you undock an Opal, it automatically starts logging data to the internal memory. The time displayed on the Opal when undocked will be used as the start time of the logged recording when you later convert it to HDF (*.h5) format.

If you find that your Opal's clock displays a time from 1970 or that its logged recordings are from 1970, it means that your Opal was fully powered off at some point. When an Opal fully powers off, the internal clock also powers off and gets reset to an epoch time of 0 (Midnight on January 1st, 1970 GMT). See the Wikipedia Page for more information on epoch (or Unix) time.

Does the clock affect the timestamps on wirelessly streamed data?

No. When data is recorded wirelessly, the clock on the host computer is used as the "gold truth". The clock will only affect the timestamps on data that is converted to HDF format from logged recordings using the "Import and Conversion Manager" in Motion Studio.

Why did my Opal power off and loose the correct time?

There are 3 ways for an Opal to fully power off:

• The battery runs out
• The buttons are used to select the "Power Off" option
• The "Power Off" button is pressed in our software while the Opal is docked, and it is then undocked

How do I set the correct time on my Opal?

• Configure your hardware from within Motion Studio or Mobility Lab
• Dock your Opal and click on the Tools->"Update Clocks" option

How do I keep my Opal from powering off and loosing the time?

Use the standby mode. Putting your Opal into standby mode greatly reduces the power consumption and keeps the clock running. Holding either of the buttons will bring it out of standby mode. You can put your Opal into standby mode in 2 different ways:

• Use the buttons to go to the power menu and go select "Enter Standby". See the User Guide for guidance on how to navigate the Opal's user interface.
• Dock your Opal and click on the Tools->"Put your sensors into standby mode" option

How can I tell which recording is which if they are all from 1970?

Each file has a sequence number in the file name, following the ID of the Opal. This number starts with "0001" for the first recording performed on the Opal. The number increments sequentially for each recording after that. If the Opal data is cleared or the memory reformatted, the number will start over again at "0001" the next time it is undocked. While this doesn't let you unambiguously determine the time of these recordings, knowing the order they were recorded in can help sort out this issue.

How do I keep the time updated when using the Opal for daily, all day logging?

• In this use case, the Opal is probably running until the battery gets low and it turns off. Before it turns off, however, it first goes into standby mode in order to keep time. By default, the Opal will go into standby mode when the battery reaches 10% of full. You can configure this level from Motion Studio's configuration tool. The 10% level should allow the Opal to keep time for 24 hours. This is typically plenty for daily use, as only several hours will likely pass before the Opal is charged at night. If charging cycles are missed, however, it is  likely that the Opal will fully power off and reset its clock 24 hours later. To cover this contingency, you may want to increase the battery cutoff to 20%.