I need a Point of sale device for my retail store customer . I am to connect this (interface?) this to the security camera DVR and cash registers. I have never worked with a POS before and need some help. What is a good one to order and what is the terminology to describe this? The store is small with 8 cameras and DVR. Customer wants to monitor live sales and record it.

A little more information is needed. While the hardware is typically the same, the software is widely different. What works for a retail store doesn't work for a carryout.

On the camera end of it, typically you have a RS232 output from the POS device goes to a device that injects an overlay with items as they are scanned.

One of the highest theft from a POS is "fake" scans where an item appears to have been scanned but it was not. The POS overlay will eliminate this.

The only limit on monitoring POS terminals is the client's wallet. You'll need both a good resolution camera and a DVR capable of recording at a decent frame rate to make it viewable when presented to the police.

I've got a good message board for hardware store owners. You might want to post over there and see if they have any advice-they have a lot of knowledge.
www.hardlinesdigest.com

This job was for a 7-11 chain store and the sales network was controlled by 7-11. There were too many complications, so we ended up passing on the POS part of the job. Thanks for the advice. I know I'll run into POS again.