Synchronization

The basic idea of synchronization is to provide a clock signal from a time source. Clock slave receives the signal from the clock provider and the devices are synchronized.

Devices can be synchronized in two different ways:

  • Software synchronization - The software synchronization accuracy is around 2-10 ms, which is enough for a simple temperature measurement. This synchronization solution requires no additional hardware.
  • Hardware synchronization - It is a hardware solution which can synchronize all USB devices (SIRIUS, DEWE-43, …) and EtherCAT devices.

We have connected one Sirius, one DEWE-43 and one Krypton measurement unit to the SBOX.

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Time source

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Time source provides a clock for synchronization. It can be selected from:

  • Dewesoft DAQ devices (when we have a Dewesoft measurement device connected to our computer),
  • External (Clock/Trigger, IRIG-B DC, NTP, GPS PPS),
  • PC clock (when we have only a computer, without a measurement device),
  • GPS devices (Dewesoft RS232 (Topcon/Javad/NVS), NMEA compatible GPS, …).

NOTE: Synchronization types are dependent and automatically adjusted from the DAQ devices connected to our system.

TYPE OF SYNCHRONIZATION

If Dewesoft DAQ device is selected as a time source, clock provider must be selected from:

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  • Automatic - This option automatically selects the best option for synchronization regarding the hardware connected to the system.
  • Standalone - Only one device, there is no synchronization between the devices needed.
  • SoftSync - This synchronization solution requires no additional hardware. The accuracy is > 10 ms.
  • Clock/Trigger - The clock of the device gives a trigger signal.
  • IRIG-B DC - It contains time-of-year and year information in a BCD format (it contains the information about the absolute time). This is the best way to synchronize the devices because it is the most exact one.
  • GPS PPS - Since the satellites are transmitting exact absolute time and better receivers usually output this pulse with a high precision (below one microsecond), we can use this technology to synchronize remote systems - and there is no distance limit.
  • NTP - Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems. It is less accurate than other methods.

DS_options_settings_devices_synchronization_synchronizationType_NTP

To enter the addresses of NTP server click the edit button near the drop-down menu. If you want to have more devices synchronized via NTP protocol, the same server address must be entered in all of them.

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When you check NTP servers, time and date of the server will show. If the server address is wrong, the check will fail.

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If the synchronization via NTP is successful, the clock next to the time will be black:

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If the sync is lost, the clock will become red and the “Sync lost” message will appear:

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SYNCHRONIZATION BETWEEN DEWESOFT USB DEVICES

Accuracy When to use Device
Clock/trigger ~ 1 us stationary Dewesoft, RoaDyn, …
IRIG-B DC ~ 1 us stationary Dewesoft, Meinberg, …
GPS PPS ~ 1 us mobile GPS receiver
NTP + 10 ms Ethernet NTP server
SoftSync + 10 ms When there is no external time source /

Any Dewesoft device can be precisely synchronized by hardware (Sirius, Dewe-43, Minitaur, DS-CAN2).

When using the NET system, there are several possibilities that can be used for synchronization:

  • Clock/trigger - relative time
  • IRIG-B DC Master / IRIG-B DC Slave - absolute time
  • GPS - absolute time
  • NTP - absolute time

Clock/trigger connection example

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IRIG-B DC connection example of one unit

  • Dewesoft device as IRIG-B DC generator

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  • External IRIG-B DC provider

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GPS PPS connection example of one unit

  • Dewesoft device has a GPS receiver

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* External GPS receiver

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NTP connection example

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SYNCHRONIZATION WITH ECAT-SYNC JUNCTION

ECAT-SYNC JUNCTION works in the same way as other Dewesoft devices. It is automatically recognized within Dewesoft X software (supported in version X2 SP4). By default, ECAT-SYNC JUNCTION will be set up to synchronize between KRYPTON EtherCAT® and SIRIUS USB.

With ECAT-SYNC JUNCTION several connection options are possible:

  • Synchronization of SIRIUS/DEWE-43 USB with KRYPTON/SIRIUSiwe EtherCAT® devices, where the accuracy of synchronization is \< microsecond.

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  • Synchronization of KRYPTON module with external IRIG B DC triggering source.

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  • Synchronization of KRYPTON and SIRIUS USB with external IRIG B DC triggering source.

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  • Synchronization of KRYPTON/SIRIUSiwe with triggered cameras.

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  • Synchronization of SIRIUS/DEWE-43 USB with KRYPTON/SIRIUSiwe and triggered cameras.

DS_options_settings_devices_hardwareConnection_syncJunction+usb_irig+cameraTrig