Manual

2
Introduction
Model 286 Features
indicates liquid level and fill/loss rate. The current liquid level is updated
and visible in many of the display modes used in configuring various
settings of the instrument.
The 4 x 4 keypad is provided for direct entry of values for setpoints, sensor
length, and other functions. The keypad also provides a convenient menu-
type interface for configuring various instrument settings that require
selection from a list of options.
1.1.4 HI/LO Alarms
Two user-defined setpoints, HI and LO, are provided for all four channels
with front panel LED indications for Channels 1 and 2. The HI and LO
setpoints may also operate two pairs of low-current, rear panel relay
contacts and a built-in audible alarm. The HI/LO relay contact pairs may
be assigned to Channels 1 and 2, or to Channels 3 and 4.
1.1.5 Controller Modes
The Model 286 provides three controller modes: normal, auto-changeover,
and pre-cool. The preferred mode can be selected via the front panel
keypad or remote interface. The level control sequence varies based on the
selected mode. See the discussion beginning on page 7 for more
information regarding the function of the controller modes.
1.1.6 Remote Operation
The Model 286 is capable of providing up to two analog 0−10 VDC signals,
which corresponds to 0−100% liquid level, accessible from the rear panel of
the instrument for use with a voltage recorder. This is a factory-installed
option and should be specified at the time the instrument is purchased.
Up to two self-powered (i.e. does not require an external power supply) 4-
20 mA current loop outputs can also be ordered as an option.
Additional digital interface options, including RS-232 or RS-422, are
available as options. The serial remote interface provides a comprehensive
command set for remote monitoring and configuration of all functions of
the instrument.