ViewSonic Vt2756-l Manual

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ProblemPossible Solution
Remote control unit does 
not operate • 
Make sure the batteries are inserted correctly.
•  Batteries could be weak or dead. Replace with new batteries.
•  Check if there is a fluorescent light illuminated near the remote 
control sensor.
•  The path of the remote control beam may be blocked. Make 
sure the path is clear and that the remote control is aimed at the 
remote control sensor on the TV.
•  Press 
 on the remote control to see if you can turn on the TV.
•  Press MENU on the remote control to see if there is an OSD 
menu shown on the screen.
•  Press only one button at a time and it is the correct one for the 
operation you want to perform.
Unit cannot be operated • External influences such as lightning or static electricity may 
cause improper operation. In this case, operate the unit after first 
turning on the power of the TV and the AVC System, or unplug 
the AC cord for 1 to 2 minutes, then replug again.
Power is cut off suddenly • Make sure the sleep timer is turned off.
•  Make sure the PC or video signal cable is connected properly.
•  The internal temperature of the unit has increased. Remove any 
objects blocking the vent or clean as necessary.
No CATV reception (or no 
reception above CH13) • 
Set the correct Signal Type (Air / Cable) on the Channel menu.
•  CATV is connected improperly or not connected; please check 
all the CATV connections.
•  The cable TV service is interrupted; please contact your cable 
operator.
•  Adjust the location of the antenna, place it far from roads or 
sources of interference.
Picture is cut off/with 
sidebar screen • 
Make sure the video signal cable is connected properly.
•  Adjust the Screen Size setting on the Picture menu.
•  Press ASPECT repeatedly on the remote control to switch to the 
display mode you prefer.
Other Information  
						

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Specifications
ModelVT2756-LVT2406-L
LCD
(LED Backlight)Screen Size
27-inch Full HD 60Hz 24-inch Full HD 60Hz
Aspect Ratio 16:9 16:9
Television System ATSC / 64 & 256 QAM / 
NTSC-MATSC / 64 & 256 QAM / NTSC-M
Program Coverage VHF : 02~13              UHF : 14~69                  DTV : 02-69
CATV : 01~125          CADTV : 01~135
Input signal RGBRGB analog (0.7/1.0 Vp-p, 75 ohms) Separate Sync,
fh: 31.5-67.5 kHz, fv:59.94-60 Hz
RF TV system Antenna / NTSC+ATSC, TV cable system /
CATV+Digital cable
Video 1 composite RCA, 1 YPbPr component, 3 HDMI
Audio 1 mini-stereo,
2 pair of RCA (L/R) stereo
USB JPEG / MP3 Format
Compatibility PCUp to 1920 x 1080 (CEA mode)
Speaker Output 5W x 2 @ THD=10% (max)5W x 2 @ THD=10% (max)
Audio Output 1 Earphone jack, 1 SPDIF 
(optical)1 Earphone jack, 1 SPDIF 
(optical)
RS232 Output RS232 communicationRS232 communication
IR control Output IR pass through signal  
(NEC 38KHz / RC5 38KHz) IR pass through signal 
 
(NEC 38KHz / RC5 38KHz)
Power VoltageAC 100~240V (50/60Hz) AC 100~240V (50/60Hz)
Operating
conditions Temperature
0°C to + 40°C 0°C to + 40°C
Humidity 20% to 90% (no condensation) 20% to 90% (no condensation)
Storage
condition Temperature
-20°C to + 60°C -20°C to + 60°C
Humidity 20% to 90% (no condensation) 20% to 90% (no condensation)
Dimensions Physical
(W) x (L) x (H)661.6mm x 180mm x 469.6mm
566.6mm x 149.2mm x 394.8mm
Weight With stand5.5 kg 4.12 kg
Without stand 5.1 kg 3.92 kg
Regulations UL/cUL, FCC, BETS-7,NRCan, CEC
Power
consumption On
35 W (typ) / 40 W (max) 25 W (typ) / 30 W (max)
Stand by 0.5 W 0.5 W
Warning: Do not set the graphics card in your computer to exceed 
these refresh rates; doing so may result in permanent damage to the 
LCD TV.
Note: Product Specifications are subject to change without notice.
Other Information  
						

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RS232 Protocol
1. IntroductionThis document describes the hardware interface spec and software protoco\
ls of RS232 interface 
communication between Viewsonic Commercial Display and PC or other control unit with RS232 
protocol.
The protocol divide into three sections:
• Set-Function
• Get-Function
• Remote control pass-through mode
h In below document, “PC” will represents all the control units tha\
t can sent or receive the RS232 protocol command.
2. Description 2.1 Hardware specification
Viewsonic LCD communication port in the rear side
(1) Connector type: DSUB 9 Pin Male
(2) Pin Assignment
Pin # Signal Remark
1 NC
2 RXD Input to LCD Monitor
3 TXD Output from LCD Monitor
4 NC
5 GND
6 NC
7 NC
8 NC
9 NC
frame GND
* Use of crossover (null modem) cable required for use 
with PC.
12345
6789
Male DSUB 9Pin (outside view)
2.2 Communication Setting
•  Baud Rate Select: 9600bps (fixed)
•  Data bits: 8bits (fixed)
•  Parity: None (fixed)
•  Stop Bits: 1 (fixed)
2.3 Command Message Reference
PC sends to Monitor command packet followed by “CR”. Every time PC\
 sends control command 
to the Monitor, the Monitor shall response as follows:
1. If the message is receives correctly it will send “+” (02Bh) followed by “CR” (00Dh)
2. If the message is receives incorrectly it will send “-” (02Dh) followed by “CR” (00Dh)
Other Information  
						

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3. Protocol3.1 Set-Function Listing
The PC can control the TV Monitor for specific actions. The Set-Function command allows you to
control the TV behavior in a remote sit through the RS232 port. The Set-Function packet format
consists of 9 bytes.
Set-Function description:
Length: Total Byte of Message excluding “CR”
TV ID: Identification for each of TV
If we want to set all TV settings, TV ID can use “99” to achieve, and
it will not have Reply command on this function.
The TV ID can be set via the OSD menu for each TV set.
Command 
Type: Identify command type,
“s” (0x73h) : Set Command
“+” (0x2Bh) : Valid command Reply
“-” (0x2Dh) : Invalid command Reply
Command: Function command code: One byte ASCII code
Value[1~3]: Three bytes ASCII that defines the value
CR: 0x0D
Set-Function format:  
Send: (Command Type= “s”)
Name LengthIDCommand 
Type Command
Value1Value2Value3 CR
Byte Count 1 Byte2 Byte 1 Byte 1 Byte1 Byte1 Byte1 Byte1 Byte
Bytes 
order 1
2~3 4 56789
Reply: (Command Type= “+” or “-”)
Name LengthIDCommand 
Type CR
Byte Count 1 Byte2 Byte 1 Byte1 Byte
Bytes 
order 1
2~3 45
[NOTE] The reply for “Power on” command is the exception. It’s 0x322B0D ( 2+).
Example1: Set Brightness as 76 for TV-02 and this command is valid
Send (Hex Format)
Name LengthIDCommand 
Type Command
Value1Value2Value3 CR
Hex
0x380x30
0x320x730x240x300x370x360x0D
Other Information  
						

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Reply (Hex Format)
Name
LengthIDCommand 
Type CR
Hex
0x340x30
0x320x2B0x0D
Example2: Set Brightness as 176 for TV-02 and this command is NOT valid.
Send (Hex Format)
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Hex
0x380x30
0x320x730x240x310x370x360x0D
Reply (Hex Format)
Name LengthIDCommand
Type CR
Hex
0x340x30
0x320x2D0x0D
Set-function table
Set  
Function Length
IDCommand 
Type (ASCII) Command
Value Range  
(Three ASCII bytes) Comments
Code (ASCII) Code (Hex)
Power on/
off(standby) 8
s!21000: STBY
001: ON
Input Select 8s“ 22000 : TV
001  : AV
002 : S-Video
003 : YPbPr
004 : HDMI
014: HDMI2
024: HDMI3
005 : DVI
006 : PC/VGA 1. No need for USB
2. For the case of 
two
more same sources,
the 2
nd digital is used
to indicate the
extension.
Contrast 8s#23000 ~ 100
Brightness 8s$24000 ~ 100
Sharpness 8s%25000 ~ 100
Color 8s&26000 ~ 100
Tint 8s‘27000 ~ 100
Color mode 8s)29000: Normal
001: Warm
002: Cold
003: Personal
Bass 8s. 2E000 ~ 100
Treble 8s/ 2F000 ~ 100
Balance 8s030000 ~ 100 Sets Balance 
position
Other Information  
						

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OSD 
language8
s232000: English
001: French
002: Spanish Extend the value for
more supported
languages
Power lock 8s434000 : Unlock
001 : Lock
Volume 8s535000 ~ 100
Mute 8s636000: OFF
001: ON (mute)
Button lock 8s838000: Unlock
001: Lock
TV channel
(DTV) 8
s< 3C 
For -0:
001~999
A00~F99
(1000~1599)
For -k:
1
st and 2nd char are 
same as -0
3
th char is
CHAR[ ASC(3th
digi)+ k x 10 ] It’s channel OSD
number but not
frequency number.
TV channel
(ATV) 8
s= 3D001~999
Menu lock 8s> 3E000: Unlock
001: Lock
Number 8s@ 40000~009
Key Pad 8sA41000: UP
001: DOWN
002: LEFT
003: RIGHT
004: ENTER
005: INPUT
006: MENU/EXIT
Remote
Control 8
sB42000: Disable
001: Enable
002: Pass through
Disable: RCU has 
no
effect on HDTV.
Enabled: RCU
controls the HDTV.
This is the power up
default on the 
HDTV.
Pass through: 
RCU
has no effect on
HDTV and all RCU
command codes 
are
transmitted to FC 
via
the RS232 port.
Setup 
wizard 8
sC43000: Disable
001: Enable Disable: to skip the
initial setup wizard
Restore
default 8
s~ 7E000 Resets HDTV to
factory setting
Other Information  
						

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[NOTE]
1. Behavior at lock modes
Lock ModeBehavior
Button Lock 1. Lock all buttons of front panel and RCU, except for “Power”
2. All the SET functions should be workable via RS32, even the ones with
according hot key in RCU like Mute,…etc.
MENU Lock 1. Lock “MENU’ key of front panel and RCU
2. The Factory and Hospitality modes should not be blocked for the 
model
using MENU-combined key to enter these two modes. Alternative 
approach
will be indicated separately if any limitation by model.
POWER Lock 1. Lock “POWER” key of front and RCU.
2. The SET_POWER on/off should be workable via RS232, but does not 
mean
the POWER lock will be released under this case.
3. Can not be un-locked by reset in OSD setting
4. Will auto AC power-on in power-lock
5. Under power-lock, the set will not enter power saving when no PC 
signal and
neither not turn off when no other video signals after 15min.
Remote control 
disable Lock the keys on RCU, but keep the buttons of front panel workable.
2. Example for value setting of SET_TV channel DTV
012-0: 0x 30 31 32
012-1: 0x 30 31 42
1012-2: 0x 41 31 52
1512-3: 0x 46 31 62
3.2 Get-Function Listing
The PC can interrogate the TV Monitor for specific information. The Get-Function packet format
consists of 9 bytes which is similar to the Set-Function packet structure. Note that the “V alue” byte
is always = 00.
Get-Function description:
Length: Total Byte of Message excluding “CR”
TV ID: Identification for each of TV
Command 
Type: Identify command type,
“g” (0x67h) : Get Command
“r” (0x72h) : Valid command Reply
“-“ (0x2Dh) : Invalid command Reply
Command: Function command code: One byte ASCII code
Value[1~3]: Three bytes ASCII that defines the value
CR: 0x0D
Other Information  
						

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Get-Function format:
 
Send: (Command Type= “g”)
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Byte Count 1 Byte2 Byte 1 Byte 1 Byte1 Byte1 Byte1 Byte1 Byte
Bytes 
order 1
2~3 4 56789
Reply: (Command Type= “r” or “-”) 
If the Command is valid, Command Type = “r”
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Byte Count 1 Byte2 Byte 1 Byte 1 Byte1 Byte1 Byte1 Byte1 Byte
Bytes 
order 1
2~3 4 56789
If the Command is Not valid, Command Type= “-”
Name LengthIDCommand
Type CR
Byte Count 1 Byte2 Byte 1 Byte1 Byte
Bytes 
order 1
2~3 45
Example1: Get Brightness from TV-05 and this command is valid.  
The Brightness value is 67.
Send (Hex Format)
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Hex
0x380x30
0x350x670x620x300x300x300x0D
Reply (Hex Format)
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Hex
0x380x30
0x350x720x620x300x360x37 0x0D
Example2: Get Brightness from TV-05 , but the Brightness command ID is error and it is 
NOT in the command table.
Send (Hex Format)
Name LengthIDCommand
Type Command
Value1Value2Value3 CR
Hex
0x380x30
0x350x670XD30x300x300x300x0D
Other Information  
						

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Reply (Hex Format)
NameLengthIDCommand
Type CR
Hex
0x340x30
0x350x2D0x0D
Get-function table
Get 
Function Length
IDCommand 
Type Command
Response Range  
(Three ASCII  bytes) Comments
Code (ASCII) Code (Hex)
Get-Contrast 8ga61000 ~ 100
Get-Brightness 8gb62000 ~ 100
Get-Sharpness 8gc63000 ~ 100
Get-Color 8gd64000 ~ 100
Get-Tint 8ge65000 ~ 100
Get-Volume 8gf66000 ~ 100
Get-Mute 8gg67000: Off
001: On (muted)
Get-Input select 8gj6A000~  See Set-function 
table
Get-Power
status: ON/
STBY 8
gl6C001: ON
000: STBY
Get-Remote
control 8
gn6E000: Disable
001: Enable
002: Pass 
through Gets RCU mode 
status
Get-Power lock 8go6F000: Unlock
001: Lock
Get-Button lock 8gp70000: Unlock
001: Lock
Get-Menu lock 8gq71000: Unlock
001: Lock
Get-Setup
wizard 8
gs73000: Disable
001: Enable
Get-ACK 8gz7A000 This command is 
used
to test the
communication link.
3.3 Remote Control Pass-through mode
When PC sets the TV monitor to Remote Control Pass through mode, the TV shall send a 7 bytes 
packet (followed by “CR”) in response to RCU button activation. Note, that in this mode the RCU 
shall have no effect on the TV function. For example: “Volume+” will not change the volume in the 
LCD but only sends “Volume+” code to PC over the RS232 port.
Other Information  
						

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IR Pass Through-Function format
 
Reply: (Command Type= “p”)
Name LengthIDCommand
Type RCU Code1
(MSB) RCU Code2
(LSB) CR
Byte Count 1 Byte2 Byte 1 Byte 1 Byte 1 Byte1 Byte
Bytes 
order 1
2~3 4 5 67
Example1:  Remote Control pass-through when “VOL+” key is pressed \
for TV-05 
Reply (Hex Format)
Name LengthIDCommand
Type RCU 
Code1 (MSB) RCU 
Code2 (LSB) CR
Hex
0x360x30
0x350x700x310x300x0D
Key Code (HEX)
1 01
2 02
3 03
4 04
5 05
6 06
7 07
8 08
9 09
0 0A
- 0B
RECALL (LAST) 0C
0D
0E
ASPECT (ZOOM) 0F
VOLUME UP (+) 10
VOLUME DOWN (-)  11
MUTE 12
CHANNEL/PAGE UP (+)  13
CHANNEL/PAGE DOWN (-)  14
POWER 15
SOURCES (INPUTS) 16
17
18
SLEEP 19
MENU 1A
UP 1B
Other Information