82
FORM 160.54-M1
ISSUE DATE: 10/25/2019
SECTION 5 - MICROBOARD 031-03630-001
JCI COMPANY CONFIDENTIAL
JOHNSON CONTROLS
relay output is turned OFF, resulting in no conduction
through the load resistor. This applies less than 1 VDC
to the microboard input. To determine the state of the
solid state relay, first confirm that +5 VDC is present
at pin 2 of the flow sensor. Then connect a voltmeter
between the microboard TP1 (GND) and the respective
flow sensor input to the microboard.
The software accommodates either the Paddle type
sen-sors connected to TB4 of the I/O Board or the
Thermal type sensors connected to either J7 or J14
on the microboard. The actual connection point of the
Thermal type sensors to the microboard is determined
by the chiller vintage (See
). On new production chillers
before June 2009, they are provided connected to the
microboard J7. On new production chillers after June
2009, they are provided connected to the microboard
J14. To ensure that the program reads the correct input,
the Flow Switch setpoint on the OPERATIONS Screen
must be set appropriately as explained in
33 - SYSTEM CALIBRATION, SERVICE SETPOINTS,
.
Serial Data Ports
Microboard 031-03630-001 is equipped with 6 serial
ports. See
. Each port is dedi-
cated for a specific function as follows:
A. COM1 (J2) – RS-232. Printer.
B. COM2 (J13) – RS-485. Modbus communications
to the Liquid Cooled Solid State Starter, Medium
Voltage Solid State Starter, Medium Voltage Vari-
able Speed Drive and Variable Speed Drives.
C. COM3 (J12) – RS-485. Hot gas bypass, Heat Re-
covery, Head Pressure Control, Motor Monitor-
ing.
D. COM4 (J2) – RS-232. E-Link Gateway.
E. COM5A (J15) – Opto-coupled transmit/receive.
VSD Adaptive Capacity Control Board or Style B
Solid State Starter.
F. COM5B (TB4) – RS-485. Future VGD actuator.
Each port is equipped with two LEDs. A red TX LED
illuminates as data is transmitted to or requested from
another device. A green RX LED illuminates as data
is received from another device. The RS-232 voltages
are industry st5 to +25 VDC and -5 VDC to
-25 VDC logic levels. The RS-485 voltages are indus-
try standard o VDC and +1.5 VDC to +5 VDC logic
levels. COM5A logic levels are 0 VDC and +5 VDC.
A diagnostic test can be performed on each serial port
to confirm proper operation. See
The LEDs and their functions are as follows:
• CR41 RX1 – COM1 serial port receive data.
• CR42 TX1 – COM1 serial port transmit data.
• CR40 RX2 – COM2 serial port receive data.
• CR37 TX2 – COM2 serial port transmit data.
• CR38 RX3 – COM3 serial port receive data.
• CR35 TX3 – COM3 serial port transmit data.
• CR39 RX4 – COM4 serial port receive data.
• CR36 TX4 – COM4 serial port transmit data.
• CR44 RX3 – COM5A serial port receive data.
• CR43 TX3 – COM5A serial port transmit data.
• CR47 RX5B – COM5B serial port receive data.
• CR45 TX5B – COM5B serial port transmit data.
Display Interface
The graphic screens displayed on the Liquid Crystal
Display are created from the program downloaded from
the Program card and stored in the Flash Memory Chip.
The data to form these screens is output from J5. This
data is in the form of red, green and blue drive signals
applied to each of the 303,200 display pixels arranged
in a matrix of 640 columns x 480 rows. Each pixel con-
sists of 3 windows; red, green and blue, through which
a variable amount of light from the Display Backlight,
is permitted to pass to the front of the display. The drive
signals determine the amount of light permitted to pass
through each window. The overall pixel color is a result
of the gradient of red, green and blue light allowed to
pass. The drive signal for each pixel is an 18 bit binary
word; 6 for each of the 3 colors. The greater the binary
value, the more light is permitted to pass. The pixels
are driven sequentially from left to right, beginning
with the top row. To coordinate the drive signals and
ensure that the pixels in each row are driven from left
to right and the columns are driven from top to bottom,
the drive signals are accompanied by a clock and hori-
zontal and vertical sync signals.
