craiga

Hi, It's hard to tell from your description whether the RS-485 network is a straight line -- although it looks like it could be. RS-485 requires that you use wiring that goes from one device to the next device to the next device to the last device. You can't connect wiring in a way that forms a T or a Y or a star at any point. You also need to have termination resistors (100 ohms) at both ends (in parallel with the devices on each end). Note there can be only two ends, if you have more ends, then the wiring is incorrect (you have a star, not a straight line). Your diagram is certainly not correctly terminated -- place a 100 ohm resistor across pair close to the connector to the AVTech DVR and turn off termination on the SC3100. You also need to have a termination turned on on the last camera -- from the diagram this doesn't appear to the the last camera (but it's not clear the wiring is a straight line). Note that most DVRs are in star networks with a cable leading from the DVR to each camera. You simply can't connect up RS-485 in the same way (and expect it to work). However you can use two pair (one going to the camera and one coming back from the camera) to ensure you keep the straight line wiring required by RS-485 even though the physical cabling is a star. -Craig

Hi, One thing is that sometimes the AVC760 will get the wrong external IP address for DDNS -- so do check that, not only is it being updated, but that the address it's updating with is correct. The problem seems to occur with some ISP's transparent proxies. Having the router do this may work better (if there's a problem). -Craig

Hi, I think you missed the step where you set up DDNS on the DVR (i did say i thought it could only be configured through the AP software -- which is maybe why you didn't see it). You have to setup the DDNS on the DVR with "dyndns", your hostname, account, and password. That way the DVR can update dyndns when the external IP address changes. Some routers can also do this and are configured similarly. I generally don't like doing this with PC/Mac software because it just introduces one more possible problem. -Craig

Hi, If you've got it already connected to the LAN, then to view from home you simply need to enable port forwarding / virtual server in your router. Before you do this, you should be able to check/change the network settings (Advanced -> Network from memory). If it is configured for a static IP address you are OK, otherwise you need to assign it a static address (some routers don't require this, but even if not required router configuration is always more complex if you use DHCP on the DVR). You should really change the PORT from 80 to 8071. The reason for changing the port is that if you want to access this from a mobile phone in the future, you are very unlikely to be able to access it via port 80. Once you've changed the port, you'll need to add the port number into the URL to access the DVR, e.g. (replace 192.168.1.10 with the static IP address of the DVR): http://192.168.1.10:8071/ Now, you just need to enable port forwarding (also known as virtual server) on the router -- this allows access from the outside world on port 8071 to get to the DVR. You'll need to find out how to do this on the client's router, but basically you want to forward: TCP port 8071 to: 192.168.1.20 (port 8071) obviously changing 192.168.1.10 to the IP address of the DVR. From memory, the following can only be configured through the AP software (not everything is accessible through the DVR menus): Lastly, unless the customer has a static IP address with his ISP (usually available at additional cost/month), the Internet IP address will change every time the router re-connects (or at other times). In order to get around this you'll need to setup a dynamic DNS name. Go to: http://www.dyndns.com/ and create a Dynamic DNS Free account. Then configure the DDNS section in the DVR configuration with your account information (select "dyndns" and enter your hostname, username, and password). Lastly you'll need to set the DNS (not to be confused with DDNS above) servers. You can get these IP addresses from the customer's ISP (support page). Alternatively, you could use the free DNS servers from http://www.opendns.com/ (appears you have to create a free basic account to get the IP addresses these days). Lastly through the AP software (only) you can setup an email to be sent on motion detect (or other alarm), which can be useful. The 760 doesn't support having this facility turned off during the day automatically, but it can be done manually, if required. Once the DDNS info has propagated, then you can access the DVR with something like: http://mydvr.dyndns.org:8071/ Hope that helps, -Craig

While this particular model has not been tested, i believe the AVC760Z is based on the AVC760 which is supported by Security View on the Mac.

Hi. A basic issue with cat5e is the voltage drop on the 24 awg wires. To compound this a lot of cheap baluns use 1 pair for power and 1 pair for video and the other 2 pair in the cat5e are left unused. Using 3 pair for power reduces the voltage drop considerably. This calculator will let you calculate the voltage drop for the number of pairs, length of cable, and power requirements of the camera you are using (note it says input around voltage and current (amps)), but what you should enter are the minimum voltage and maximum power requirements of the camera: http://www.netkrom.com/voltage_loss_over_cat5_calculator.html Many cameras allow a range of input voltages (e.g. 12-24VDC). If you use an 18 or 24VDC power supply for such cameras, then the voltage drop is unlikely to be an issue. If you use a 12VDC power supply in this instance then you will almost certainly have problems: some cameras still function, some with function with lots of video problems, some will work as long as the IR lighting doesn't come on, some won't function at all when the voltage isn't high enough (but it's never a good idea). You can measure the voltage at the camera end with a simple voltmeter but do this with the camera attached, otherwise you'll see no voltage drop at all. -Craig

One thing that can be quite useful is to have the motion detect working -- so you are alerted to movement around the house (when you are at home or not or both). In order for motion detection to be useful you need minimise false alarms. Some things to consider, YMMV... Downward facing cameras don't work well for motion detection if you have pets. From directly above, humans and cats are about the same size and many dogs appear much larger -- this makes it impractical to try to discriminate between human motion and pet motion which may mean lots of false alarms depending on where your pets can roam. Best is to position cameras so they are looking from the side (along the front, back, etc. side of the house). Humans will be much taller than pets and you can configure motion detection to more easily ignore the much smaller looking pets from this angle. Perspective becomes an issue -- if you are too low then a pet closer to the camera will appear larger than a human -- you'll still need multiple cameras to cover one side of a house well because people will appear too small to detect easily at the other end of the house. It takes some thought, but good placement of cameras makes them much more useful for motion detection alarms. Bushes. Obviously if your camera can only see walls, decking, paving and no greenery then you will have less problems with bushes setting off motion. Although shadows cast by moving trees etc. can be worse, so you're not necessarily completely in the clear just because the camera can only see walls and concrete. You can mask areas, but depending on the camera angle that isn't a solution. Bits of greenery much smaller than humans in the image aren't really much of any issue. Spiders. Spiders love the space between the shield that sits above many IP66 bullet cameras. It's a perfect hiding place and they can build their web around the camera and walk over the lens all the time. You don't want this. Removing the shield will greatly reduce spiders (fine if the camera is mounted under the eves), however bullet cams and their mounts provide lots of complex spaces that are perfect for building webs. Vandal-proof dome cameras provide far less of a home for spiders. Seal any places were insects can get into the housing or behind it (if there are any) with silicon. Insects setting off alarms continuously are not helpful. The SVB-56IRC80L650D and SIR-4160 cameras would be great homes for spiders in my opinion -- although you may have less of a problem if they are highly exposed to the weather... I'd be inclined to use a camera in the darkest back area that had no LEDs. And i'd be somewhat more inclined to use an Sony Exview chip camera rather than the Super HADs you are using everwhere else (it's more sensitive). And place two IR illuminators separate from the camera (mounted as far away as practical from the camera to illuminate the scene well -- the same as you would do to light with visible light). This should provide better illumination of the scene, and prevent insects flying near the camera from appearing as giant super brightly lit ghosts (and setting off the alarm). Note that motion detection when you are covering a wide area, particularly from a high vantage point, can be impractical because humans appear far too small. Dome cameras. I like the turret dome cameras (even though they require silicon to seal up the insect houses that the housing forms) because i get occasional condensation inside my real dome cameras (IP66 by itself can't stop this from happening). The turret domes don't really have any space inside -- the glass is flat and the lens sits right up against it (just like a bullet camera). You can get the same 1/3" sony super had ccd chip in this style. YMMV... Make sure the angles covered by the lenses you get on the cameras are the right choice for their location. -Craig

Hi. Wireshark's the only way to go then. Not sure what happened to their website -- try back in a bit, it's not working at the moment... -Craig

Hi. Well you are not supposed to use ports under 1024 for this purpose, so preventing you from using ports under 2000 isn't really surprising. Keeps you from causing trouble by using well known ports like 143 Anyway, whatever port you are using for 8000 -- did you try forwarding both TCP and UDP on this port? I can't work out an argument that would explain what you are seeing as a result of not forwarding UDP packets, it is very possible this is a problem though... Also, have you looked for any logs on the DVR? These might provide some info. Anyway if forwarding UDP doesn't work, get a copy of wireshark ( http://www.wireshark.org/ ) and analyse what's happening. It will give you more clues. If the traffic on port 8000 is UDP -- then the situation can be explained by traffic being blocked in one direction only -- the server doesn't get any indication that you are still connected and so quits sending video. The other thing is that if the traffic is TCP, the Chinese do send forged TCP resets (RST) to both ends when they want to block traffic -- they actually allow the connection to initiate, and then block it because they don't like the content (some ISPs use the same to prevent some peer-to-peer technologies). You'd also see TCP resets if your ACKs weren't being received (high packet loss or blocked in one direction after the connection was initiated). Both problems would explain the 3 seconds of video and then nothing. Running wireshark at the other end will provide more information, but bear in mind the situation is more complicated; see: http://wiki.wireshark.org/CaptureSetup/Ethernet for details. -Craig

Hi. Try changing port 8000 to 143 (imap) or 110 (pop3) or 23 (telnet). It's not likely these ports are outright blocked by the authorities because they are in such high use (although it's not out of the question they could still be filtered). The chinese do force connections on HTTP to drop when a keyword is transmitted that the government doesn't like -- it's possible they do this on all TCP traffic -- in which case it's a huge problem if the protocol on default port 8000 contains an innocent keyword that's (now) banned. It certainly would explain what you are seeing. Setting up a VPN would get your traffic out of China unscathed, but whether or not this is a useful solution for you depends on where you want to access it... -Craig PS: transparent proxies won't necessarily affect all locations equally, so just because it can be accessed within China is no indicator that transparent proxies are not involved. But since you've changed ports away from the eighties and still have the problem, it's very unlikely to be the problem.

Hi. The 3 second problem can be related to interference by aggressive transparent caches. If you use port 80, 8080, 8000, 81, or 8081 externally (across any part of the Internet), then the likelihood of problems by transparent caches is significant. Don't use these addresses. If you are connecting from an office network that has a proxy server, then the problem is highly likely to be the proxy server (and you can't fix the problem by changing the port). The solution would be for the administrator to disable caching for the IP address associated with the DVR within the proxy server itself. -Craig

IP can just be a means of transferring a digital signal -- and one that is so ubiquitous and cheap and flexible that any other solution is almost certainly going to be more expensive, less flexible, and ultimately less widely used. Relatively inexpensive analog video to IP adapters and ethernet-over-coax adapters are available to integrate IP solutions with existing equipment/infrastructure. The cost differences between IP-based digital solutions and analog solutions will continue to erode to the point where analog is dead. Non-ip based high-def solutions are unlikely to play anything more than a niche role in the future.

Hi, That's great. 81 is fine if it works for you. -Craig

Hi, Third party native Mac s/w is available for some DVRs. Google the DVR name along with downloads and with the site limited to Apple's web site. E.g.: avtech downloads site:apple.com (it's the best way to find mac software for any application.) -Craig

Hi. If you are using port 80 (or even 8080) to connect from eagle eyes, you might want to try changing the port forwarding on your router (and on the DVR if needed) to use a different port (like 8061). Mobile operators do all sorts of nasty stuff to traffic on port 80 to reduce bandwidth use that can cause all sorts of problems. -Craig