Installation issues

[smartec 0]

Hi all,

 

I have got a question here regarding my installation problem.

Such a weird thing happens here, my installer tested the camera on LCD testing monitor

and it showed image on the testing monitor. It seems normal.

However, when my installer plugged in camera into the DVR, the DVR recognizes the camera

as VIDEO LOSS. Testing monitor used are the BNC-RCA type, and the DVR is using BNC-BNC type. Any idea on what has happened here?

 

Any input is so much appreciated here.

 

Regards,

 

Howard

SMARTEC

[smartec 0]

Anyone has any idea regarding this?

I have my brain stuck on this for few days, and haven't found the solution yet.

It will really help to have any suggestion.

 

Thank you in advance.

 

Regards,

 

Howard

[rory 0]

Hi, couple things to check.

 

1-Bad Video Cable

2-Bad Connections

3-Too Long a run

[Soundy 1]

Wow, so many questions, so little info.

 

What DVR is this? Does it need the input to be "enabled" in the setup? Did your installer connect his monitor directly to the camera end, or at the DVR end of the cable? What type of cable is being used? How is it terminated? What happens if you plug into another input on the DVR? How many cameras are they? Are they all showing this problem, or is it just one? If just the one, have you tried swapping it with another one on the DVR?

[smartec 0]

@soundy: the DVR is standalone DVR. I do not see any input to be "enabled" in the setup. The weird thing is from 20 cameras that I installed, only 5 of them display images on DVR, the rest of 15 cameras do not display any image on the DVR. However, when I test the camera using the 3.5" LCD Testing Monitor, all 20 cameras display the image on the Testing Monitor.

 

My installer connect his monitor at the DVR end of cable, not at the camera side. And the cable used are RG-6 cable with various distance. Few of them are with 3000 feet long, some of them are 150 feet long. Bad connection could be one of the issue, but one of the camera with the distances of 3000 feet shows image, but the one at 150 feet doesnt even show any image. And for the one with 3000 feet, we are using video amplifier to boost the signal.

 

I have also tried to change into different DVR. But, the same thing happens, only 5 cameras display the image.

 

Any more idea of what is going on?

 

Thank you for any advice.

 

Regards,

 

Howard Ng

[rory 0]

Is the Cable Copper in and out? Not Cat TV cable right? If the signal is not strong enough some DVRs will not see it, while a simple LCD/TV input would. Even the short distance cameras, the connectors might not be done properly and then could get a bad signal.

 

Have you tried the cameras that arent showing up on the DVR, on the channels which are showing cameras?

[smartec 0]

@rory: It's RG6 coaxial cable. Any idea on testing how strong the signal is?

The thing is some of the cameras are okay on the DVR, not all of them, which make

me confused. If all the camera is not find, then it's easier to find out the solution to it.

 

I have tried plugging the cameras that arent showing up on the dvr into the channel which

are showing cameras, and it still doesnt show anything on the dvr. So, my guess the dvr is fine

at the moment. What do you think?

 

Thank you for the insight though.

 

Regards,

 

Howard

[Soundy 1]

If you can find one, pick up a 75-ohm terminator (or try just putting a 75-ohm resistor across the tip and shield of the BNC connector at the camera end).

 

Then with an ohmeter/multimeter, measure the resistance across the tip and shield at the DVR end of the cable. You should get very close to 75 ohms (certainly within the 70-80 ohm range).

 

Anything outside that will be an indication of a physical cabling problem.

[Harrar 0]

What types of cameras are you using? 12VDC or 24VAC? All powered locally at the camera end, I assume.

 

Personally, I'd have my installer reterminate both ends of one of your bad cameras and see what happens. Next, I'd grab an O'scope and check to see if you're getting your video signal at the proper level at the DVR end.

[smartec 0]

@harrar: i am using 12 V DC camera, and it's done locally at the camera end, so i am assuming

the camera power isnt the problem here, but i will check it again whether it's because of the power that i am getting at the camera end. Hopefully it's the power problem.

 

@soundy: i personally will do that for sure to check the signal strength of each camera. If the case

is the ohm meter shows that it's outside than the acceptable range, do you think i should re-wiring the camera again? or there is a device to help me on that?

 

thanks for the help guys, i really appreciate it.

 

regards,

 

howard

[tomcctv 187]

@harrar: i am using 12 V DC camera, and it's done locally at the camera end, so i am assuming

the camera power isnt the problem here, but i will check it again whether it's because of the power that i am getting at the camera end. Hopefully it's the power problem.

 

@soundy: i personally will do that for sure to check the signal strength of each camera. If the case

is the ohm meter shows that it's outside than the acceptable range, do you think i should re-wiring the camera again? or there is a device to help me on that?

 

thanks for the help guys, i really appreciate it.

 

regards,

 

howard

 

 

you will also need to find out what amp your power supply is and make and model of your cameras and how far away from your dvr are they.

[Soundy 1]

I doubt it's a power-supply issue, or the cameras would be dropping out regardless of whether he's connected to the test monitor or the DVR. One way to double-check this, though, might be to use a T-connector to feed the camera to both the DVR and the monitor at the same time.

 

If the cable resistance readings are too far out of line, it may indicate the need to re-pull those runs. This could be confirmed by just stringing the run across the floor and hooking it up, before pulling it through its final route. BTW, the test load doesn't HAVE to be 75 ohms; I suggested that only because 75-ohm terminators are relatively common. The impedence rating is nominal for design operating frequencies, but the cable should really have near-zero resistance at DC. Any size resistor will do; a multimeter should read within a couple ohms of the resistor's rating either way.

[smartec 0]

@tomcctv: The amp that PSU using is 1amp 12V DC, and the cameras have various distances to the DVR, some of them are about 2500 feets, and some of them are about 150 feets. One of the camera that has distance of 2500 feets shows on the dvr, but the rest of them do not show on the dvr. But when we are using LCD Testing Monitor, we can see all of the camera.

 

@soundy: I will try to use the T connector too, and see whether it works. I will let you guys know about it. But has anyone encountered this so far?

 

thanks for the input again guys. will let you guys if i can solve it.

 

regards,

 

howard

[tomcctv 187]

@tomcctv: The amp that PSU using is 1amp 12V DC, and the cameras have various distances to the DVR, some of them are about 2500 feets, and some of them are about 150 feets. One of the camera that has distance of 2500 feets shows on the dvr, but the rest of them do not show on the dvr. But when we are using LCD Testing Monitor, we can see all of the camera.

 

@soundy: I will try to use the T connector too, and see whether it works. I will let you guys know about it. But has anyone encountered this so far?

 

thanks for the input again guys. will let you guys if i can solve it.

 

regards,

 

howard

 

you have a power problem. 1amp over 750m will not run a camera. do they have seperate power supplys and at which end are they powered.

[rory 0]

you have a power problem. 1amp over 750m will not run a camera. do they have seperate power supplys and at which end are they powered.

 

I think he said he's powering them locally at the cameras .. that was my first thought .. i had to go back a few posts

 

I would still verify whether it is RG6 CAT RV Coax with aluminum braid, or RG6 Copper in and out.

With some DVRs if the signal is not strong enough, even if you plug it into a monitor you may get a picture, but when plugged into the DVR could be video loss. bad cable, bad connectors .. maybe even bad power .. could do all that too. Going by what he said it doesnt sound like the DVR is the problem.

[smartec 0]

@tom : the cameras are powered locally, what i mean by 750 meter distance is the distance of running the video cable.

 

@rory : what i can possibly think now is the power is not grounded properly, because i have one

issue before whereas the camera could show video loss for quite some times, and after a while

it goes back to display some images. really hope that is the case. all the rg6 coax that i used are

copper in and out for sure, what are the differences of the aluminum and copper one? what do you the solution is if the signal is not strong enough? get an amplifier?

 

regards,

 

howard

[Soundy 1]

With some DVRs if the signal is not strong enough, even if you plug it into a monitor you may get a picture, but when plugged into the DVR could be video loss.

Could be that the DVR is set for 75-ohm termination on the lines, which is loading them too much and the signal is dropping out. The test monitor would more than likely be "Hi-Z" loading and therefor not causing the signal to drop.

[rory 0]

True Soundy ..

 

smartec, you say it is 750 metres .. 2500 feet?

What kind of amplifiers are you using right now?

Ive never run coax that far before, maybe someone that has can jump in.

[smartec 0]

@soundy: i am using video amplifier which can reach 1 km distance, just for information, one of the camera that has distances of 2500 feet shows on the DVR. The weird thing is even the 150 feet camera doesnt show anything on the DVR.

 

@rory: "Could be that the DVR is set for 75-ohm termination on the lines, which is loading them too much and the signal is dropping out. The test monitor would more than likely be "Hi-Z" loading and therefor not causing the signal to drop." I believe most of the DVR takes 75 -ohm as their input, doesnt it?

 

Thanks for the help,

 

Howard