Hello
I have two CR6 dataloggers and I want to keep their clocks synchronised. Is there any instruction allowing clock adjastement.
Thanks.
Various options:
If the loggers are connected to an internet connection then you can use the Networktimeprotocol instruction to sync them both to a NTP server. The accuracy of this depends on the NTP server and on variable delays in the network. Errors could be 100 ms or so.
If the loggers are connected to a local Pakbus network or they could be connect to each other via a wired connection, then you can sync the loggers to each other (using the CRBasic PakbusClock and Clockreport instructions). Typical errors between loggers may be a few tens of milliseconds depending on the logger and the network.
If the loggers are independently connected back to a PC running Loggernet you can setup Loggernet to check and set the logger clocks at regular intervals. However you then are using the PC time as the reference point and even a network timed sync'ed PC will have clock drift of some seconds or more. In addition variations in the comms delays to the logger (if over GPRS for instance) can add additional and variable offset, of a 100 ms or so.
If you are not so bothered about the times in the loggers matching just the synchrony of the measurements then, via a wired link, you can get one logger to trigger the measurements in another. See the help for the Waitdigtrig instruction.
Finally, in the next release of the CR6 operating system we will also introduce the GPS functionality we have in our other loggers. This is with a GPS receiver and of course sight of the sky you can synchronise the logger clocks, to within a 100 microseconds or so, to GPS time. That operating system is due out in the next few weeks.
Tank you very much for you help