Campbell RWIS STATIONS Instruction Manual - page 6
RWIS Stations
2
Theory of operation
The NL110 provides communication for all system devices, converts logger
measurements to NTCIP compliant data, routes images from an installed
camera to the logger, provides SNMP communication, and stores text
generated in the CR10X to text values required by NTCIP.
Customers call in through the modem and establish a PPP connection. This
connection makes a private network and has its own IP address.
The NL110 also provides the necessary function for providing NTCIP
compliant data to ANY NTCIP compliant software that can interrogate NTCIP
compliant systems. This makes the RWIS system compatible with other
systems supplied by other manufacturers.
The logger makes all measurements. As they are made, output is generated
that the NL110 accepts. The NL100 then converts the data to NTCIP
compliant values by changing the variable names to variable names that
comply with the specification.
The camera installed outputs an image automatically on a fixed interval. As
the image is sent, it is routed from the camera to the 10 base t input on the
NL110. The NL110 then routes the image to the logger for later use. One
image is stored in the logger, and when a new image is sent, it replaces the
image last sent.
All sensors have their own measurement instructions, but there are some
unique setups for the equipment installed in the ESS. The following pages
describe those setups.