Data & Power Connections - Cygnus 1 Operation Manual

DATA & POWER CONNECTIONS
The Cygnus 1 ROV Gauge can be electrically-connected by one of two methods, depending
on suitability :
Independent-Cable Connection
This is a single cable connecting the Gauge to the surface.
This cable can be supplied, on request, by Cygnus.
This cable is independent of the ROV's own cabling and has a maximum length of
1000 metres
ROV Local-Termination Connection
In this method the connection from the Gauge is taken to the ROV, and is merged
with the ROV's own cabling to connect to the surface
It is essential that the Data-connections from the Gauge are maintained throughout
as twisted-pair
Power for the Gauge can be taken from the ROV's own power supply, if suitable
The Data-output from the Gauge has a maximum capability of 1000 metres :
if the distance from the Gauge to the surface is greater than 1000 metres the Data-
output from the Gauge must be electronically buffered within the ROV.
Independent Cable Connection
Recommended cable connection for direct-cabling from Cygnus 1 ROV Gauge to the
computer at the surface :
Cable-termination : for long cables it may help to fit a 120 Ω resistor, in series with a 1
nF capacitor, between the TX+ and TX- connections inside the 9-way D-type plug.
See datasheets on the supplied CD for the K3 receiver, and MAX483 line driver.
Installing the Gauge
21