Watlow MLS - Manual (Page 24)

12 MLS User’s Guide
Introduction
The eight digital inputs are referenced to the MLS controller common;
an open input pulls them High (Off). When you short the input to
controller common the input goes Low (On). Do not connect external
power sources to the MLS' digital inputs.
Front Panel Description
The MLS-PM's panel mounted LCD screen and touch keypad provide
an intelligent way to operate the MLS. The on-board display driver
operates the liquid crystal display. The LCD has 16 alphanumeric or
graphic characters per line; it is backlit for viewing under low light
conditions. The 8-key keypad and on-board keyboard scanner allow you
to change the MLS' operating parameters, controller functions, and
displays.
The MLS' information-packed displays show process variables,
setpoints, and output levels for each loop. A bar graph display, single
loop display, scanning display and an alarm display offer a real-time
view of process conditions. Two access levels allow operator changes
and supervisor changes. The front panel looks like this:
MLS RTB Technical Description
Here's a picture of the RTB: