Sync Problems after 300ft

title says it all. has anyone had problems with an AP recieving sync at or above 300ft from the cmm?

I have not, however I can see how you might.

The sync pulses’ peak to peak voltage is only 3V, so voltage drop over the 300’ cable + induced noise can disrupt the sync pule enough that the AP can’t read it.

You can try higher quality shielded cable with RF chokes at each end, and/or get the CMM closer to the AP’s.

yea we have the CMM’s mounted about 9-10 feet off the ground. and im pretty sure were using double shielded cable but still seem to be having problems recieving sync.

Put CMM higher on the tower … Ethernet is not designed to work well past 300 ft (especially on low temp…we see this all the time up in Canada)

We actually, we try not to go past 250ft to avoid problems…

Motorola is coming out with their new CMM… it runs 30Volts (this is supposed to help when getting close to the 300ft mark)

I’d expect trouble getting anything over 300’. As jerico said - you are probably hitting the limits of the signal. Ethernet can only go 100 meters on 24 AWG because of voltage loss, capacitance increase, and electrical propagation time (cannot be greater than 50ns IIRC). I suspect something similar with the timing pulses.

Just out of curiosity, why did you decide to mount your CMM so low? (IE as opposed to with the APs up top - see more GPS satellites that way as well)

it wasnt my choice to mount them there. this site was built 4 years ago when the company was first starting, and needless to say there are no employees left from that time. Our AP’s are at 320’. Ill talk to our climber and see what we can do about moving them higher.