Rs485....grrrrrrrrrrrrrrrr

[breff]

Right,

2 dennard 2060 domes, Dedicated Micros DS2, telemetry down the coax no problem all okeydokey.

However this is then connected into a Vista Smartel so I wanted to use the 485 bus.

Addressed the domes (01 and 02), checked the termination resistors were turned on, used cat5 (a single twisted pair) between 1st dome to DM(terminal block on back Bus A + and -) then on to 2nd dome. (I was going to add the smartel after getting this working)

Set serial telemetry to Dennard and individual camera telemetry to Dennard as instructed by DM Tech Support, do you think the buggers would move, my AR53 would they.

Checked resitance of 485 line at DM, approx 60 ohms, indicates cable good (2 120ohm eol resistors in parrallel)

I gave up in the end and switched back to coax control.

What am I doing wrong???

[JB_]

No need to terminate both domes , just terminate the END dome on the wire. Had a problem in past with a DS2 myself where too many terminations (although accidental) were stopping any ptz control.

[Guest]

No need to terminate both domes , just terminate the END dome on the wire. Had a problem in past with a DS2 myself where too many terminations (although accidental) were stopping any ptz control.

Aha, knew there was something not right about that '2 120ohm in parallel' bit, but I was tired whilst reading it!

Clue in the question, line termination resistor, for terminating the line i.e. across the data pair - at the end of the run.

[breff]

The DS2 is in the middle, isnt there supposed to be a resistor each end?

[JB_]

used cat5 (a single twisted pair) between 1st dome to DM(terminal block on back Bus A + and -) then on to 2nd dome

Sorry misread it, does the DS2 have dip switches on the back for its own termination? (which would make 3 terminations). Switch that off if it's in the middle.

[breff]

I dont think it has, will it be ok to use 1 pair in the cat 5 to the first dome, then bring it back to the DVR on another twisted pair in the same cat5, then join it to the 2nd cat5 going to the 2nd dome?

Then I'll turn off termination on the 1st dome.

[Gopher]

I dont think it has, will it be ok to use 1 pair in the cat 5 to the first dome, then bring it back to the DVR on another twisted pair in the same cat5, then join it to the 2nd cat5 going to the 2nd dome?

Then I'll turn off termination on the 1st dome.

yes it will be okay as long as you make it like this

DVR -> Dome 1 -> connector -> Dome2 -> termination resitstor

so that the DVR and each camera are in paralell with each other and that one end is terminated, that's all that's needed.

Hope this clears it all up. I've had this problem as well, except try looping 6 domes into 1 rs485 loop where everything comes back to a central point! cabling nightmare, but that's another story..

[breff]

Gopher, I'll give that a go.

I suppose I should have tried each dome 1 at a time as well.

[Gopher]

Gopher, I'll give that a go.

I suppose I should have tried each dome 1 at a time as well.

No problem, i know exactly what ya mean.

[Guest stevie]

Gopher especially when you get the video pair mixed up for the 7th time ..............................you know what i mean.........lol!!!! See you at the papermill for the camera fits!!!!