timezone

[cglaeser 0]

I've been testing a demo version of exacqVision software DVR for the past few days and there are a few areas that could use improvement, but overall, my impressions of this application are favorable. However, there is one design decision that is, well, IMO, just plain wrong. Time stamps are an important feature in a DVR system, and the system must sync up all the times among all the various devices such as DVR and cameras and the events that each can produce. As part of their design, the Exacq engineers have decided to set the timezone of the DVR to the correct time zone and then set the timezones of all the attached cameras to GMT 0. Hello?

 

IP cameras are becoming increasingly sophisticated with CPUs and embedded operating systems and support for protocols such as ftp and sendmail and event scheduling and on and on. Many of these features are time based, and if the timezone is wrong, then the features don't work as expected.

 

For example, the most recent Axis firmware release will generate ftp folder and file names based on date and time. Awesome! This is a fantastic feature, because it is now possible to create folders on the fly and thus avoid the huge number of file names in one folder, which can bring any OS to its knees. Of course, if the timezone is wrong, then this feature does not work as expected. Event scheduling is wrong. Date/time video overlays are wrong. And on and on. It's just all wrong.

 

Perhaps most surprising is that when I talked to Exacq tech support, I expected them to say, oh, that's a known defect and we hope to fix that in the next release, or there is a workaround, or something like that. But, as it stands, this is the intended design, and the implementation works as designed. Of course, they don't claim to support ftp or camera-generate time overlays or any other time-related feature supported by the camera. Wow. Do any other DVRs work this way?

 

I'm just a bit stunned that someone would design a system where many of the devices attached to LAN are intentionally set to the wrong timezone. Comments?

 

Best,

Christopher

[bpzle 0]

Did they say what the benefit of this was?

[cglaeser 0]

Did they say what the benefit of this was?

 

Yes. They claim they need to do this in order to implement the search feature. Here's the basics of their implementation. The exacqVision server sets all the camera time zones to zero. In addition, all the camera NTP servers point to the exacqVision server. When a camera periodically requests the current clock time from the exacqVision server, it gives them the wrong time, which is offset by the GMT time zone. In other words, they set the time zones to 0 and then add the time zone to the clock time.

 

It's an engineering kludge just so they can avoid a simple time adjustment during the search. Now, it's just inertia. They implemented a stupid hack that works fine for dumb cameras and they don't want to spend time fixing it. However, as cameras become more capable, the limitations of this kludge become more apparent. In addition, it's not ONVIF compliant, because cameras may be connected to multiple devices from different vendors. If one vendor expects the correct clock time and time zone and another vendor expects the wrong clock time and time zone, there will be a problem.

 

Best,

Christopher