Can I recover old data?

[Jacey 0]

I wonder if someone might help me with a query.

 

I have a Vistron "AHD.DVR-4V" CCTV system which is set to record and review over a 30 day period.

 

The unit contains a hard drive which I suspect is way bigger, in capacity, than is required to record just 30 days.

 

At the end of each 30 days, the unit starts counting the next thirty days - meaning that the Menu only allows me to review each past 30 day period.

 

I am wondering if means it automatically over-writes the earlier recordings or simply only make the past thirty days available through the menu, yet write to different area(s) of the hard drive, which would make it technically possible to recover the older recordings through interrogating the drive via either and/or a PC or Mac.

 

Has anyone any experience of retrieving old data, in this manner, who would be willing to advise please?

 

If it is possible, would I need any propriety software?

 

I have made enquiries of the manufacturer (based in Singapore) but suspect the unit may actually be a generic model being marketed under a variety of guises and the "manufacturer" seems disinclined to even acknowledge my email enquiries of them.

 

Thank you.

[the toss 0]

This is what "usually" happens. You set your frame rate and resolution. This results in a recording capacity depending on the size of your hard drive. Recording is done in "blocks" - often 2Mb. So when you first power up an installation there will be nothing available for viewing until that first block of 2Mb is recorded. Similarly when overwriting , it is progressively done in 2Mb blocks. If yours is set up this way then the only way to extend recording capacity is to install a bigger hard drive or or drop your frame rate/ resolution settings.

The other way some can be set up is to nominate a recording storage period ( lets say 30 days ) and the frame rate / resolution is automatically adjusted to enable that period to take place