This page is a "leaf" on a tree with information about remote sensing. It is a leaf of the branch about putting an IP camera (a bit like a webcam, or CCTV) on your LAN, either for local viewing, or, if you want to "open the doors", viewing from afar across the internet.
If you are just getting started with using IP cams, you may want to visit an overview of using IP cams I have provided.
Ad from sponsor, only distantly related to viewing images from afar:
My basic FarWatch system only requires a PC which you are willing to leave running and an internet connection. For about $40 you can add hardware to monitor temperature at the premises. That is just a start. With FarWatch, you can monitor many, many things. And my ArduServer lets you do similar things for even less, if you can "drive" an http://www.arunet.co.uk/tkboyd/ele1psa.htm.
But! Back to the point of this page: Information about a specific IP cam. (IP cams are like webcams, but they connect to a LAN via TCP as opposed to connecting to a single PC, e.g. via USB). Here you will find information specific to one camera... see my page with more general points about setting up IP cams.
(I managed to buy a new TP-Link TL-SC4171G via eBay, 1/14 for £30... but I was lucky: The seller was new, had no reputation, but was in fact genuine.)
There are major overlaps between the camera this page is primarily about, the 4171, and another model: TP-SC31714G. The former has pan/tilt, the latter does not. Alas, they share seemingly identical provisions for setting their internal time of day/ day of year systems. I failed, after much struggle, 24 Feb 19, with software "published 1 Nov 2011, TL-SL4171G_1.6.18P12_12110", semingly most up to date at 2/19, to get the synchronize with NTP server to work. Sigh. But if your set the date/time by hand, the camera DOES seem to understand post Y2K, at least.
I don't have time to do a full review here... but I wanted to get the technical note below out on the web for you.
In a nutshell... I like the camera! Has a nice interface. Has features I want. Seems to WORK!...
All this, of course, qualified with "good for the (list) price".
Credit were due: When I sent an email to the TP-Link tech support eddress, I did get a reply. That helped me solve a problem I'd been unable to solve before. I think some of the information from TP-Link was wrong... but enough was right that I was able to make progress. Sigh. But this level of support way ahead of what you get from some!
The examples which follow assume that your camera is not using your LAN's DHCP server, but rather has a fixed local address of 192.168.0.254
Much can be done, just using your LAN. Certainly get all LAN based things working before you go on to attempt WAN access. When you are ready for that, the text here assumes that your router has an external, WAN, IP address which is known to the internet generally by means of, say, MyRouter.dyndns.org, by the magic of DDNS, or some other "dynamic directory name server" service.
If you have only one http server on your LAN, it can be at the standard port, 80, and you do not need to explicitly specify it. For the sake of the examples, we will assume that you camera has been put on port 81, so explicitly specifying a port can be illustrated. Just drop the ":81" which appears in many of the lines below if you are using the default port 80... or use ":80"... it will do no harm, and remind you to put the port in, if you go beyond one server. Which you would do if you added another camera, for example.
Default admin user: "admin". Default password: "admin".
To fetch a "snapshot" from the TP-Link TL-SC4171G, (and SC-3171G, I believe) the "magic code" is....
... the first being the code you use if you are on the same LAN as the camera, the second being the code to access from afar, over the internet. (The second will also work "across" the LAN, but you will be "going around the houses".) (I won't be repeating the two variations after this, you have to remember they are there, use them as needed. The ":81" can be left out if you are using the standard port 80 for your IP cam, as discussed earlier.
You will probably need to have logged into the camera at some point before the above will work.
My thanks to iSpyConnect.com for that. I look forward to trying their software one day... looks good! Their page is always worth checking about such things. There may be additional commands you can issue which will determine resolution, etc.
(I also offer general notes on digital inputs and outputs on IP Cams.)
Exec summary: Feed +12v to the right pin, and the camera will take a picture. Details follow...
The TP-Link TL-SC4171G has a connector block on the back of the base. Four places to connect a wire.
a) "Connect a wire": You need to use a solid, not stranded wire. To connect, just push it carefully into the hole. To DIS-connect, used a small screwdriver, thumbnail, etc... but not anything too sharp... to press on the "thing" above the hole, and the wire should come away easily.
Now... naming of parts... I am going to call the four connecting points "terminals" "1", "2", "3" and "4", numbering left to right, i.e. "4" is the terminal closest to a corner of the base of the camera.
What you see, if you are looking at the back of the base of the camera, from "behind" it.... ("A"= where wireless antenna attaches). (If you have one of the "hardwired only" devices, you may well find two of the connecting points marked "DI+" and "DI-". They would be, respectively, what I have called "1" and "2".)
----------------------------- | | | A 1 2 3 4 | | | -----------------------------
Terminals 1 and 2 seem to be the right places to connect a digital INput to the camera. (You can make it do neat things on seeing an input... for instance take picture, move in pre-programmed ways, etc. No need to rely on the software/ image based "motion" detection... which isn't very useful for outdoor scenes.) If you apply 12v to pin 1, with that 12 volt's ground connected to pin 2, then 7.3mA will flow, and the device will "see" the voltage.
The web interface speaks of the alarm being raised by a "high" or a "low" on the digital input.
I think this is wrong. I think what they meant is that you can choose between positive edges... i.e. a CHANGE in the voltage from 0 to 12... and negative edges to trigger the alarm.
A diagram I received from TP-Link said that 5v was suitable as an input. When I applied 4.8 volts, the device did not "see" it.
I've moaned a lot. I DO like the camera. TP-Link can have good engineers, even if they cut a few corners in the documentation and interface text departments, can't they? And cut corners mean lower prices. When you see me claiming my web-pages are perfect and complete, you may infer criticism in the above. In the meantime, I am just trying to forestall confusion.
Terminals 3 and 4 are the digital OUTput... I think that they simply connect to the contacts of a relay, but TP-Link sent me a diagram suggesting that the output might be polarized, and if it is, and if the diagram is correct, then the current should flow in terminal 3 and out terminal 4.
The web interface says you can set the output to be "high" or "low" when the device wants to send an alarm. However, I think those terms should be "closed" and "open" (or visa versa).
TP-Link say the output is good for 12 volts, but doesn't specify what current it can carry.
(Remember: I also offer general notes on digital inputs and outputs on IP Cams.)
For now: Yes... I've managed to get the TL-SC4171G to do FTP.
Page has been tested for compliance with INDUSTRY (not MS-only) standards, using the free, publicly accessible validator at validator.w3.org. Mostly passes.