108
FORM 160.54-M1
ISSUE DATE: 10/25/2019
SECTION 7 - LIQUID CRYSTAL DISPLAY
JCI COMPANY CONFIDENTIAL
JOHNSON CONTROLS
Displays can be operated in Fixed Mode or Display En-
able Mode. In Fixed Mode, the first pixel drive signal
is applied a fixed number (48) of clock (CLK) cycles
from the end of the HSYNC pulse and the drive signals
are terminated a fixed number (16) of CLK cycles be-
fore the next HSYNC pulse. In Display Enable Mode,
the pixel drive signals are applied to the pixels only
while ENABLE signal is present. This signal is typi-
cally present 4 to 48 CLKS after the end of the HSYNC
pulse and 2 to 16 CLKS before the next HSYNC pulse.
All YORK applications operate in the Display Enable
Mode. The state of the ENABLE (Display Interface
Board J1-27) signal from the microboard places the
Display in the desired mode as follows:
• SHARP LQ10D367/368 (031-01774-000) and
LQ104V1DG61 (031-02886-000) Displays -
When ENABLE maintained “low”, display oper-
ates in Fixed Mode.
• LG SEMICON Display (031-02046-000) does
not have the Fixed Mode feature.
As described above, in OptiView Control Center appli-
cations, the Display scan is left to right, beginning with
the top row and continuing sequentially through the
rows to the last row. However, in Display applications
other than OptiView Control Centers, image reversal
is sometimes required. In image reversal applications,
the scan is reversed; the scan is right to left, beginning
with the last row and proceeding to the top row. The
Scan Mode is determined by the configuration of wire
jumpers on the Display Interface Board (See
Displays by different manufacturers can require differ-
ent timing and control signals. The microboard must
know which Display is present in order provide the
correct signals. Therefore, when AC control power is
first applied to the OptiView Control Center, as part of
the power-up sequence, the microboard reads the Panel
ID wire jumpers P1D0 - P1D3 on the Display Interface
Board and determines which Display is present. It can
then provide the correct timing and control signals to
produce the graphic image, as required by the Display
manufacturer. Since the Display Interface Board iden-
tifies the Display for the microboard, there is a differ-
ent Display Interface Board required for each Display
application and each has a unique jumper configura-
tion that identifies the Display. A complete explanation
of this process is included in the preceding Microboard
section and the Display Interface Board section that
follows.
The DC power source to operate the Display is provided
by the microboard J5. Some Display manufacturers re-
quire +5 VDC; others r3.3 VDC. The position
of Microboard Program Jumper JP2 determines which
of these power sources is supplied to the Display. JP2
must be positioned according to the Display manufac-
turers requirements. Refer to Program Jumpers.
The Backlight Lamp provides the illumination for the
display. Average lamp life is 25,000 hours (2.9 years).
Some displays use one lamp. Others use two lamps.
Lamps are replaceable, but not interchangeable be-
tween different displays. Each Display manufacturer
specifies the required lamp for their display. Refer
to replacement parts list for appropriate replacement
lamp. Service replacement lamps are stocked in the
Baltimore Parts Center.
The lamp is illuminated by applying a high voltage
AC (500 to 1500 VAC) to it. This illumination voltage
is created from a low level DC voltage (+12 VDC or
+5 VDC as required by the Display manufacturer) by
the Backlight Inverter Board. Lamp brightness is con-
trolled by varying the high voltage AC. The greater the
voltage the brighter the illumination. The lamp is con-
trolled by ON/OFF commands and brightness control
signals applied to the Backlight Inverter Board from
the microboard. The microboard Program determines
when the lamp is turned ON and OFF and the lamp
brightness. Each Display manufacturer specifies the
Backlight Inverter Board to be used. Therefore, it will
vary according to the Display manufacturer.
The LQ104V1DG81 has and LED backlight and does
not use a Backlight Inverter Board.
The ribbon cable that connects the microboard to the
Backlight Inverter Board also varies according to the
Display manufacturer’s requirements. See
. Microboard
Program Jumpers JP3, 4, 5, 7 and 8 determine the volt-
age levels of the control signals sent to the Backlight
Inverter Board and must be configured per the Display
manufacturer’s requirements as listed. A detailed de-
scription of the operation of this board is in the Back-
light Inverter Board section that follows. Also see the
preceding Microboard section for a detailed descrip-
tion of the Lamp Dimmer circuit.
The actual Display that is installed in the OptiView
Control Center of the new chiller is determined by the
Display manufacturer contractual agreement in place
during the time of OptiView Control Center produc-
tion. Displays stocked for Service replacement are a
