More Ptz Help

[Steevo25]

Hi All,

I presently have a SMart2 DVR and a PTZ Dome. Both work together exactly as they should and I am more than happy with them. At present it is just a one-to-one connection between the DVR and the Camera using CAT5e twisted pair cable for RS485 and a seperate video and power cable. The cable run is about 14metres.

I am about to add another PTZ camera which is about 20metres cable length away from the DVR. The new PTZ camera is the the complete opposide side of the premises to my first PTZ. Now my question is, what is the best way to wire these up. I don't really want to have a cable running from the DVR to the first camera and then another wire running from that camera to the second one as that means the cable is coming all the way back on itself looking messy and increasing the cable length unneccessarily. Can I just have 2 wires coming from the RS485 port on the DVR one going to each camera. The reason I ask is that there are no termination options on the DVR and also there are no termination options on either of the cameras. I don't know how the line it terminated at present but it all seems to work ( only one camera installed at present ).

Basically it means there will be a wire coming from the first camera and going to the DVR and then another wire going from the DVR to the 2nd camera so the DVR is in the middle of the bus. Is this the way it is usually done? As you can probably tell, this is my first exposure to PTZ cameras and RS485.

Many thanks in advance.

[Alpat Systems]

In general the recommended way to run RS485 is in Daisychain, i.e looped from one dome to the next etc etc. The last dome is then fitted with a terminal resistor (120ohm). Most PTZ's have this built in and activated via jumpers/dip switch. The resistor is there to keep the signal stable. As your using CAT5e just for transmission your currently only utilising one pair of cables. DVR>PTZ, so you've got another 3 pairs within the CAT5e cable not being used. Why not "loop" another pair back at the PTZ head, so then you'll have a signal back at the DVR end, you can then simply extend this cable onto your next dome.

Just make sure you document this as the colour of the cables will be different at each PTZ head.

There's a few other ways to do it e.g Daisy chain with spurs, Star method. RS485 distributor (star wired data distributor) but simple daisychain is the easiest method.

[Steevo25]

Thats an excellent suggestion that I didn't think of about looping another pair back then extending it at the DVR.

I definately cannot find any form of termination on either camera. There is one bank of 8 dip switches on each camera. 2 switches for the baud rate and 6 switches for the ID. There are no jumpers or anything in the on-screen menus about the termination and there is nothing mentioned about it in the manual. I could just put a 120ohm resistor across the terminal blobk where the cable connects to the last one.

In general the recommended way to run RS485 is in Daisychain, i.e looped from one dome to the next etc etc. The last dome is then fitted with a terminal resistor (120ohm). Most PTZ's have this built in and activated via jumpers/dip switch. The resistor is there to keep the signal stable. As your using CAT5e just for transmission your currently only utilising one pair of cables. DVR>PTZ, so you've got another 3 pairs within the CAT5e cable not being used. Why not "loop" another pair back at the PTZ head, so then you'll have a signal back at the DVR end, you can then simply extend this cable onto your next dome.

Just make sure you document this as the colour of the cables will be different at each PTZ head.

There's a couple of othe ways to do it e.g Daisy chain with spurs, Star method. but simple daisychain is the easiest method.

[Alpat Systems]

Thats an excellent suggestion that I didn't think of about looping another pair back then extending it at the DVR.

I definately cannot find any form of termination on either camera. There is one bank of 8 dip switches on each camera. 2 switches for the baud rate and 6 switches for the ID. There are no jumpers or anything in the on-screen menus about the termination and there is nothing mentioned about it in the manual. I could just put a 120ohm resistor across the terminal blobk where the cable connects to the last one.

What make/model is the PTZ?

I've seen an install before where the installation engineer has forgotten to activate the resistor yet its still worked, this was in a single camera install same as yours but with a PTZ keyboard (This had an inbuilt resitor). You may find though once you've got 2 Domes they may not function as expected.

[Steevo25]

Its the one here http://www.y3kvision.com/acatalog/3k33.html#aXSD27ZDN2

I am going to ring up and find out how you terminate these. I do get the occassional problem and this could be due to termination.

Sometimes when I pan/tilt etc it does it twice even though I only told it to do it once, and sometimes it ignores the command altogether.

I have also had one instance where I panned left and the dome didn't stop it just kept going round 360 degrees continuously until I did a quick pan right.

Generally it works fine with the very occassional exception of the above.

What make/model is the PTZ?

I've seen an install before where the installation engineer has forgotten to activate the resistor yet its still worked, this was in a single camera install same as yours but with a PTZ keyboard (This had an inbuilt resitor). You may find though once you've got 2 Domes they may not function as expected.

[Alpat Systems]

Its the one here http://www.y3kvision.com/acatalog/3k33.html#aXSD27ZDN2

I am going to ring up and find out how you terminate these. I do get the occassional problem and this could be due to termination.

Sometimes when I pan/tilt etc it does it twice even though I only told it to do it once, and sometimes it ignores the command altogether.

I have also had one instance where I panned left and the dome didn't stop it just kept going round 360 degrees continuously until I did a quick pan right.

Generally it works fine with the very occassional exception of the above.

I'm not familiar with that dome, and after looking at the spec/price on the website I personally wouldn

[Steevo25]

Could I just ask what is bad about it. When I was looking for a PTZ I looked at loads of them, all at around this price and some a little more. I even viewed a few and this was the best I could find in advertised end user sales at a reasonable comparative price ( non trade ). The image I get from this in day and night mode is fantastic, extremely crisp. There are also lots of features in the on-screen menu that they don't seem to mention on the website.

I'm not familiar with that dome, and after looking at the spec/price on the website I personally wouldn

[Service Engineer]

* Dual mode Super High Resolution CCD sensor provides very good quality Colour images in low light conditions of 0.01 lux or above and B/W images in low light conditions below 0.5 lux and in complete darkness with the addition of Infra Red lamps.

* Mechanical IR filter prevents focus shift in B/W mode.

* Ideal for use in difficult lighting scenes such as reading a car's number plate when the headlights are on.

* Sony 1/4" Super HAD CCD image sensor for 550 TVL resolution images and 0.01 lux low light sensitivity.

* X-vision IXC1HQDN Digital Signal Processing (DSP) chip which has been optimised for internal or external viewing and features Automatic Gain Control, Automatic Electronic Iris, Auto White Balance, Back Light Compensation, Low Smear, Edge Enhancement, Zero Colour Rolling, Super Dynamic Range and Day/Night.

* 3.25 to 88.0mm (1

[Alpat Systems]

Could I just ask what is bad about it. When I was looking for a PTZ I looked at loads of them, all at around this price and some a little more. I even viewed a few and this was the best I could find in advertised end user sales at a reasonable comparative price ( non trade ). The image I get from this in day and night mode is fantastic, extremely crisp. There are also lots of features in the on-screen menu that they don't seem to mention on the website.

First thing for me it

[Steevo25]

It just shows how we all have different requirements.

I specifically shortlisted this one because I wanted 12V rather than 24V. I have a 12V distribution box that supplies 20amps to all my cameras. Some I looked at were 24V but when I asked if they sold the power supplies they said they only sold 12V power supplies there even though they sold a 24V camera ( seems strange ). It seems an awful lot easier to get 12V power supplies than it was to get 24V.

Although it doesn't seem to say on the web, it actually has a wiring block inside that says Alarm Input 1-4 and Alarm Output 1-2. The camera also supports alarm tracking on the 4 alarm inputs ( not that I use it or have any intention of using it ). The other thing I liked is that it has a thing called a guard function. If the camera is not used for 10 minutes then it returns to a preset direction. This is great because it is over looking out front porch so if I forget to put it back there it does it automatically.

The only gripes I have found is that although the night mode is pretty good ( it gives a fairly crisp image ), it is not quite as good at night as some of my other cameras. During the day, the image is excellent. Also, the internal fan is, I think, a little noisy. You have to be quite close to hear it but its a bit noisier than others I have seen, it has only ever come on a couple of times ( well that I have noticed anyway ). The camera other than that is completely noiseless even when panning at full speed and standing right next to it.

The only thing I can't find is anything to do with termination.

First thing for me it