RH CGS-240, Manual

Page: 54 / 148

Subsystems
CGS-240 Manual 6/15/2021
Page 54 of 148
Figure 6.3
12 VDC POWER SUPPLY
The 12V DC power supply is used to provide DC power to the monitor on
the front panel only.
When the front panel switch is enabled, the 5V DC activates the solid-
state relay, SSR6, which activates the 12V DC power supply, PSU2, which
turns on the front panel monitor.
24 VDC POWER SUPPLY
The 24V DC power supply, PSU3, provides power to nearly all functions of the main control system. It provides
power to the PC, the main controller board, some heaters, motors, sensors, relays and solenoids. When the front
panel power switch is enabled, 5V DC from PSU1 activates the solid-state relay, SSR6, which applies AC power to
the 24V DC power supply. Which, in turn, activates the PC, the control computer, and remainder of the system.
6.1.2 EMBEDDED CONTROL BOARD
The Embedded Control Board, ECB,
operates the humidity generator by
performing all functions required for
system control and humidity generation. All
temperature, pressure, flow, and liquid
levels are continuously monitored and
controlled by actuation of valves, relays,
pumps, heaters, and other outputs. It
communicates to the outside world (for
instance, to the embedded PC) through one
of three independent bidirectional RS-232
serial communication ports. All data and
control parameters are communicated via
these serial ports.
The humidity generator’s ECB software
resides within the ECB’s Flash memory. The
ECB software consists of RHS custom
developed code, coupled with a high-speed
multi-tasking real-time operating system.
Via this multi-tasking embedded software,
the ECB orchestrates the second-to-second
operation of the humidity generator based
Figure 6.2