Strange CCTV

Spearmint · Aug 25, 2015

Any CCTV masters around tonight?!

We're on a site at the moment finalising a CCTV setup consisting of five PTZ cameras from ESP with the video/data and power being supplied through CAT5e (one per camera) and a control cable (RS485) parallel connecting the cameras to a controller also from ESP. Cameras 1 > 4 work fine but the moment you connect the RS485 cable to the final camera you cannot control cameras 3 > 5! The first two cameras can still be controlled however. The video is fine but you cannot move them with the controller or access the OSD. Even the video coming back from the final camera is fine... removing the control cable from the fifth camera restores the control to the others.

It almost sounds like the total resistance of the control cable is too high when bringing the final camera into play but one of the others has tried linking out the control cable between cameras 4 +5 with a bigger CSA to no avail.

It makes no sense!

telectrix · Aug 25, 2015

volt drop? underpowered PSUs?

Spearmint · Aug 25, 2015

telectrix said:
volt drop? underpowered PSUs?

Well the power is being supplied from a single unit called a PowerCat, this is feeding all the cameras. I've actually suggested taking the supplied camera PSU right up to the camera rather than using the CAT5e but I'm challenged with "well it moves about fine during startup so it can't be that"

The control cable is powered from a singular unit also so it could just be volt drop when adding in the final camera, only way around that would be to pull in some bigger cables I think.

telectrix · Aug 25, 2015

or fit some local ( to the cameras) PSUs.

DuaneMHunt1976 · Aug 25, 2015

Rs485.I only know.the connections.from computers
8bit joystick port
Pc serial port

And a.strange modem.cable, you tried a different cable
With I the.RS422 looking the same as.RS485 just.connected a bit different

Not my.area at all

Swcfisher · Aug 25, 2015

Check the address on the 5th camera

tazz · Aug 25, 2015

Over the rs485 network, ID switches are usually used, are they correctly addressed to each camera.
Plus last camera on the rs485 network again usually has a resistor installed.
Are you using baluns to convert video to twisted pair..?

Spearmint · Aug 25, 2015

telectrix said:
or fit some local ( to the cameras) PSUs.

Yeah that's what I'll be trying next, even just to test it out.

Swcfisher said:
Check the address on the 5th camera

tazz said:
Over the rs485 network, ID switches are usually used, are they correctly addressed to each camera.
Plus last camera on the rs485 network again usually has a resistor installed.
Are you using baluns to convert video to twisted pair..?

Yeah each camera has a unique address, it's set by dip switches on these. The final camera has been tried both with and without the EOL resistor activated, makes no difference. Yes they're connected with baluns, CAT5e > balun > splits to power and RG59 for video at the camera end.