Synchronizing Sensor Sampling Times

Sensor sampling can be synchronized across a group of devices based on the device's internal clock. This ensures consistent sampling times for all devices in the group, rather than relying on individual device reboots and sampling intervals.

---

Default Behavior

By default, sensor sampling is not synchronized with the device clock. After a device reboots, sampling occurs based on the configured sampling interval (group_sample_interval_sec). Since devices typically reboot at different times, sampling across multiple devices is unsynchronized.

---

Synchronized Sampling

When synchronized, all devices in a group sample at the same time according to the configured interval. Each device aligns its sampling schedule with the clock during every sampling event.

---

Steps to Synchronize Devices

1. Assign Sensors to the Same Group

• Navigate to Devices in the left pane.

• In the Sites Tree pane, select the device name.

• In the right pane, go to the Configuration tab.

• Locate SampleGroup > GROUP and assign the sensors to a common group (e.g., Group 1 or Group 2).

2. Enable Clock Synchronization for the Group

• For each sensor in the group: a. Locate group_sample_interval_type in the configuration. b. Click the current value of group_sample_interval_type and select Set Setting. c. In the Set Setting window, choose INTERVAL_SYNCED from the drop-down list.

3. Save and Reboot the Device

• Save the configuration changes.

• Verify the device reboot as follows:

  • Go to Devices in the left pane and select the device in the Sites Tree pane.

  • In the right pane, click the Commands tab. A Reboot command should appear after a few seconds.

  • If no reboot command appears, manually reboot the device:

    • Click Actions > Reboot in the Device Information pane.

4. Apply Changes

• The configuration changes and reboot will take effect after the device contacts the server.

• The device will reboot 2 minutes after the next transmission and synchronize with the clock.

---

Sampling Behavior After Synchronization

• At reboot, the sensors associated with the group will begin sampling at intervals aligned with the top of the hour.

• For example:

  • If the device reboots at 17:45 and the sampling interval is set to 10 minutes, the sensors will start sampling at 18:00 and every 10 minutes thereafter.

---

Expediting Synchronization

To expedite synchronization, force a transmission by swiping the magnetic activator key over the embossed logo on the device. This will:

• Put the device into calibration mode.

• Trigger immediate sampling and data transmission to the server.