PJLink Class2
Application Guideline
Version2.10

2024.3.22

Revision history
Version.

Release date

Note

2.00

2016.12.13

Released Version 1.00

2.01

2017.4.1

Update contents table

2.02

2017.4.10

Update contents table, change the size of “Sent AVMT command flow chart”

2.03

2017.4.19

Error correction

2.10

2024.3.22

Authentication compatibility added

Disclaimer
1. JBMIA shall NOT make any guarantees and supports on this application guideline.
2. JBMIA shall NOT owe the duty of inquiries, corrections, version up or maintenance on this application guideline.
3. JBMIA shall NOT be responsible or liable for any damage or loss, including loss of revenue or profit, by the use of or
reliance on this guideline regardless directly or indirectly.

1

Contents
This is the guideline for the development of the PJLink application software.

1-

Cautions .......................................................................................................................................................... 3

1-1.

Cautions for the development of PJLink application software ...................................................... 3

1-2.

Cautions for the test of PJLink application software ..................................................................... 5

2-

Purposes of commands................................................................................................................................... 7

3-

Timing of getting information ......................................................................................................................... 13

4-

Recommendation of the control procedure ................................................................................................... 16

5-

4-1.

Preparation .................................................................................................................................. 16

4-2.

INPT command ........................................................................................................................... 17

4-3.

POWR 1 command ..................................................................................................................... 18

4-4.

POWR 0 command ..................................................................................................................... 19

4-5.

AVMT command ......................................................................................................................... 20

4-6.

AVMT ? , INPT ? ......................................................................................................................... 21

4-7.

All Commands (All commands working during power off) .......................................................... 22

4-8.

Status information commands .................................................................................................... 23

System example ............................................................................................................................................ 24

5-1.

Multi screen system .................................................................................................................... 24

2

1- Cautions
1-1. Cautions for the development of PJLink application software
1

There are projectors and displays which are allowed only one connection to a TCP/IP port at thesame time. (e.g. TCP/IP port No. 4352 of projector or display ”A” )Disconnect the connection as soon as the transmission completes in case of using two or more

Answer2

controllers at the same time.

Slow responses may occur at some commands in stand-by mode.
Change the setting of timeout. Generally, response time is different from each other. Also

Answer3

stand-by mode may be delayed response time more than operating mode.

There are invalid commands in stand-by mode. (e.g. input change, AV mute and so on)
Refer to the recommendation of the control procedure on this manual and to the user’s manual

Answer4
Answer5of the equipment.

There may be no connection time for several seconds right after turning on and turning off.
Retry a few times. [Note] There might be no connection at all after turning off due to thesettings of projector and display.

Projectors or displays may NOT receive any commands during warming up or cooling
down.
Refer to the recommendation of the control procedures. The status can be found by theAnswercommand “POWR?”

3

6
Answer

7

The remote controller may be delayed during the transmission of PJLink command.
Adjust the transmission interval time when to send continuous commands.

ERR3, no receiving term of command, may be received as a command response.
Adjust the transmission interval time. ERR3 may occur due to the status of the projector or

Answer8
Answer9

the display. Refer to the recommendation of the control procedure on this manual.

There is no definition of the password of projector or display.
Refer to the user’s manual of the equipment.

There are both PJLink class 1 and class 2 equipment in the same network.
Confirm all projectors and displays in the network by using command “CLSS?”.
The equipment of class 1 do NOT work with the command dedicated class 2.

AnswerThe commands dedicated class 2 can NOT be used for class 1 equipment. ERR1 should
be received then. The commands of class 1 can be used for both class 2 and class 1
equipment.

10

The parts of header and class are different from each other. The response of projector anddisplay rely on the received class.
The commands from class 1 add “1” to the response.
Correct: %1POWR、%2SNUMWrong: %2POWR、%1SNUM

AnswerThe commands from class 2 reply as a class 1 command when to send class 1 header.
The commands from class 2 reply as a class 2 command when to send class 2 header.
%1INPT ? → %1INPT=30%2INPT ? → %2INPT=3Z

4

1-2. Cautions for the test of PJLink application software
1
Answer2

Answer

You may need to wait for some minutes to reboot a projector or display.
It is the characteristic of the equipment.

You may need to wait for a while to reboot a projector or display when to unplug the power cableand plug it again soon.
It is the characteristic of the equipment.

The life time of the lamp might be shorten if you unplug the power cable without cooling.
3
The brightness might be decrease if you unplug the power cable without cooling.
Answer4

Answer5

Answer6
Answer

Refer to the users manuals of the equipment.

AV mute may be cancelled when the input signal or resolution are changed or pull out the signal
cable.
The AV mute status of PJLink application software may be changed due to the specification of the
projector or display.

The power on-off repeating may have a impact on lamp life or brightness of the projector.
Generally, it is NOT good for the lamp. Refer to the user’s manual of the equipment. Prepare an
optional lamp accordingly.

Projectors or displays cannot be controlled for some minutes right after turning on or turning off.
Take care of this characteristic when to develop PJLink application software.

5

7

Answer8

AnswerPJLink application software does NOT work.
Check the equipment whether PJLink are supported or not. Also some projectors and displays
can disable PJLink or network function. Refer to the user’s manual of the equipment.

There is no definition of the password and the name of projector or display for class 1.
Refer to the user’s manual of the equipment. Other method from class1 should be used if PJLink
application software can do that.

6

2- Purposes of commands
CommandPower control

Application
To turn on and off the equipment.

POWR

Power on/off status

1

To confirm the status of power on or off.

2

Some commands are NOT set or got at the status of power on or
off.

POWR ?
(Refer to the recommendation of the control procedure on thismanual)Input change
To change the signal input mode.
INPT
Check input mode

To confirm the current signal input.

INPT ?

Audio and Video can be off temporary without power off.
It can be used below situations.
AV muteAVMT

1. A presenter wants other audiences to look at him/her.
2. A presenter does NOT want other audiences to watch his/her
documents temporary, such as a secret information.
3. Start up images of the PC.
4. When to reboot a projector soon. It is difficult for some projectors.
5. To avoid looking at projector light directly by a presenter.

7

CommandApplication
To confirm the status of AV mute.
[Note 1] There are some invalid commands while AV mute is on.

Check the status of AV mute
AVMT ?

(Refer to the recommendation of the control procedure on thismanual.)[Note 2] AV mute may be cancelled when the input signal or
resolution are changed or pull out the signal cable.

To confirm whether projectors and displays are working normally or
not.
Check the error status
ERST ?

1.

Internal error, such as fan or lamp failure.

2.

Required filter maintenance3.

Temperature failure[Note] There is no rule that projectors and displays have a failure
sensor. No error or no warning responses are sent with theequipment.

To confirm the status of the lamps.
Check lamp number and lamp time
LAMP ?

1. Usage time of lamps.
2. The number of lamps (If it is multiple lamp equipment.)[Note] In case of displays (or other “no lamp equipment”), ERR1
should be sent.

8CommandCheck signal input list
INST ?

Application
To confirm the list of available signal inputs.
[Note] An external extension input box may NOT be found.

To get the name of the equipment. This function can be used for
Check the name of the equipment
NAME ?

below situation.
To distinct the equipment one by one.
[Note] PJLink class1 is NOT defined how to name theequipment. Refer to the uses manual of the equipment.

Check the brand nameTo confirm the brand name of the equipment.

INF1 ?

To control the equipment for each brand.

Check the model nameTo confirm the model name of the equipment.

INF2 ?

To control the equipment for each model.

Check other information
INFO ?

Check PJLink class

To confirm other information[Note] It depends on each equipment.

To confirm PJLink class of the equipment.

CLSS ?

9

CommandApplication

To confirm the serial number of the equipment.
Check the serial number
SNUM ?

To distinct the specific equipment from same models.
[Note] Each model has each expression method of the serial
number.

Check the software version
SVER ?

To confirm software version of the equipment.
[Note] Each model has each expression method of the software
version.

Check the name of input terminal

To confirm the name of the signal input terminal

INNM ?

[Note] This data gets UTF-8.

Check the input resolution
IRES ?

Check the recommended resolution
RRES ?

To confirm the resolution of the signal input of the equipment.
To confirm whether the signal input is correct or not.

To confirm recommended resolution of the signal input.
This data is NOT XGA or WXGA but the number of horizontal dots
and vertical dots.

10CommandApplication

Check the filter usage time

To confirm the filter usage time of the equipment

FILT ?

To confirm maintenance timing based on the filter usage time.

Check the lamp part number

To confirm the option part number of the lamp.

RLMP ?

To exchange the lamp based on this part number.

Check the filter part number
RFIL ?

To confirm the option part number of the filter.
To exchange the filter based on this part number.

To control audio volume (internal or external speakers)
Volume control
SVOL[Note] The command may NOT be valid at volume max or min.
The volume can be changed step by step. It is NOT absolute value.
The numbers of volume max and min have different from each other.

To control microphone volume.
Microphone volume control
MVOL[Note] The command may NOT be valid at volume max or min.
The volume can be changed step by step. It is NOT absolute value.
The numbers of volume max and min have different from each other.

11

CommandApplication

To control freeze function of the equipment. This function can be used
Freeze control
FREZ

for below situation.
a. A presenter does NOT want other audiences to watch his/her
documents temporary, such as a secret information.
b. Start up images of the PC.

To confirm the status of freeze.
[Note 1] There are some invalid commands while freeze function is
Check the status of freeze
FREZ?

on.
(Refer to the recommendation of the control procedure on thismanual.)[Note 2] Freeze function may be cancelled when the input signal or
resolution are changed or pull out the signal cable.

123- Timing of getting information
Timing ofCommand

Timing of the status change

getting
information

Power ON/OFF status

The status may change when to use a remote

POWR ?

controller.

Check input mode

The status may change when to use a remote

INPT ?

controller.

Regularly

Regularly

1. The status may change when to use a remote
Check the status of AV mutecontroller.
2. AV mute may be cancelled when the input signal Regularly

AVMT ?

or resolution are changed or pull out the signal
cable.

Check the error status
The timing cannot be found.

Regularly

The lamp usage time is added during operating.

Regularly

ERST ?
Check lamp number and lamp time
LAMP ?
The status cannot be changed.
[Note] The status might be changed when an
Check signal input list
INST ?

external extension input box is connected.
[Note] The status might be changed when aremovable media, such as USB memory is inserted
or pulled out.

One time(e.g. when to
open theapplication
software)
One time

Check the name of the equipment
NAME ?

The status cannot be changed.

(e.g. when to[Note] The status may be changed when the name isopen thechanged.

application
software)
One time(e.g. when to

Check the brand name
The status cannot be changed.
INF1 ?

open theapplication
software)13

Timing ofCommand

Timing of the status change

getting
information
One time

Check the model name(e.g. when to
The status cannot be changed.

INF2 ?

open theapplication
software)Check other information

INFO ?

One time
The status cannot be changed.

(e.g. when to[Note] The status might be changed when the

open thefirmware of the equipment is upgraded.

application
software)
One time

Check PJLink class
CLSS ?

(e.g. when to
The status cannot be changed.

open theapplication
software)
One time(e.g. when to

Check the serial number
The status cannot be changed.
SNUM ?

open theapplication
software)
One time

Check the software version
SVER ?

The status is changed when the software version is
updated.

(e.g. when to
open theapplication
software)Check the name of input terminal
INNM ?

The status is changed when the name of the input
terminal is changed.

Regularly

14

Timing ofCommand

Timing of the status change

getting
information

Check the input resolution
IRES ?

The status is changed when the signal input
resolution is changed.

Regularly

One time(e.g. when to

Check the recommended resolution
The status cannot be changed.
RRES ?

open theapplication
software)Check the filter usage time
The filter usage time is added during operating.

Regularly

FILT ?
One time
Check the lamp part number
The status cannot be changed.
RLMP ?

(e.g. when

to

open

the

application
software)
One time

Check the filter part number
The status cannot be changed.
RFIL ?

(e.g. when

to

open

the

application
software)Check the status of freeze
FREZ ?

The status may change when to use a remotecontroller.

Regularly15

4- Recommendation of the control procedure
4-1. Preparation
You may need to change the settings of projectors or displays in order to use PJLink. Refer to uses manualof the equipment.
e.g. preparation
・

Activate PJLink function.

・

Deactivate the security functions of the equipment.

・

Activate network function of the equipment.

・

Deactivate “network off at stand-by mode” function.

16

4-2. INPT command
The command may NOT work at the specific status.

e.g. AV mute, Freeze mode.

①

Confirm that the response of POWR ? is “1”.

②

Confirm that the response of AVMT ? is “30” (AV mute OFF) in order to confirm AV mute status.

③

Send INPUT command.

④

Re-send the command with the increase of the length of the intervals when the response is ERR3.

Set the conditions of timeout and numbers of retrying of the application software properly against various
statuses of the projectors and displays.
Send INPUT command flow chart
Start

1
Confirm power status by POWR
command

The response
“1”

Y

2
Confirm AV mute status by
AVMT commandN

The response
“30”

N

Y

3
Send INPUT command

The response“OK”

N

The response“ERR3”NYY

4
INPUT change
successful

Wait a second

Send INPUT command
failedEnd17

4-3. POWR 1 command
Check that the equipment is OFF.
① Confirm that the response of POWR ? is “0”② Send POWR 1 command.
(The status is NOT changed at power on when to send POWR1.)
Re-send the command with the increase the length of the intervals in case of getting other than “OK”.
ERR4 may indicate the error of the equipment.

Set the conditions of timeout and numbers of retrying of the application software properly against various
statuses of the projectors and displays.

Send POWR1 command flow chart
Start

1 Confirm power status by
POWR command

The response
“0”

N

Y

2

Send POWR1 command

The response
“OK”

N

Y

Power ON successful

Banned Power ON or
Power error

Send POWR1 command
failedEnd18

4-4. POWR 0 command
Check that the equipment is ON.
① Confirm that the response of POWR ? is “1”② Send POWR 0 command.
(The status is NOT changed at power off when to send POWR 0.)
Re-send the command with the increase the length of the intervals in case of getting other than “OK”.

Set the conditions of timeout and numbers of retrying of the application software properly against various
statuses of the projectors and displays.

Send POWR0 command flow chart
Start

1
Confirm power status by
POWR command

The response
“1”

N

Y

2
Send POWR0 command

The response
“0”

N

Y

Power off successful

Banned power off or
power error

Send POWR0 command
failedEnd19

4-5. AVMT command
Check that the equipment is ON.
① Confirm that the response of POWR ? is “1”② Send AVMT command.
③ Re-send the command with the increase the length of the intervals in case of getting other than“OK”
Set the conditions of timeout and numbers of retrying of the application software properly against various
statuses of the projectors and displays.

Send AVMT command flow chart
Start

1
Confirm power status by POWR?
command

The response
“1”

N

Y

2
Send AVMT command

The response
“OK”

Y

N

The response“ERR3”
Y

AV mute successful

Wait a second

N

3
Send AVMT command
failedEnd20

4-6. AVMT ? , INPT ?
Check that the equipment is ON.
① Confirm that the response of POWR ? is “1”The response is ERR3 in case of power off.
Set the conditions of timeout and numbers of retrying of the application software properly against
various statuses of the projectors and displays.

Send “get command” flow chart (Only commands working during power on)

Start

1
Confirm power status by
POWR? command

The response“1”
NY

Send the command

The response
successfulN
The response“ERR3”NYY

Get the command
successful

Wait a second

Get the command
failedEnd21

4-7. All Commands (All commands working during power off)

Send “get command" (All commands)
Start

Send “get command”

The response
successfulN
The response“ERR3”NYY

Get command
successful

Wait a second

Get command
failed

End

22

4-8.

Status information commands

Use UDP protocol for the status information
Projectors and displays send status information command to registered IP addresses when to detect the changeof the status. These commands are LKUP, ERST, POWR and INPT.

Status information flow chart
Start

Receive a command

IS thecommand
LNUP?

N

Is thecommand
ERST?

Y
Y

N

Is thecommand
POWR?

N

Y

Is thecommandINPT?

NYCorrect

Incorrect

End23

5- System example
5-1. Multi screen systemThe condition of the system example
2 x 2 multi screen system by using four projectors and/or displays.
Signal source of all equipment are RGB 1.
Each equipment receives the signal of a quarter of full screen size.

The example of the control
Power on and display images at all of the equipment.
Power off at all of the equipment.
Set AV mute at all of the equipment.
Display images at all of the equipment.
Set same input source at all of the equipment.

[Note]To power ON at the same time at all of the equipment is NOT recommended to avoid rush current.
To turn ON of AV mute or input change at the same time at all of the equipment is recommended.

24

6. Authentication compatibility
Depending on the controller and projector/display combination that makes up the system, supporting
different levels of security, there may be multiple connection procedures. This guideline describes
protocols for all possible combinations that may occur. Please refer to this guideline to help confirm
compatibility.

(MD5), Projector/Display (MD5/SHA256) With authentication

Controller

Projector/Display

Connection establishment

Connects to TCPController (SHA256), Projector/Display (SHA256) With authentication

Projector/Display

Controller

Connects to TCPConnection establishment
Generates random number

Generates random number

Generates hashvalue from random
number +password

Sending PJLINK 1 + random number(4-bytes)

Sending hash value + command

Sending PJLINK 1 + random number

Recognizes security level

PJLINK 2

Generates random
numbers (controller)

Sending PJLINK2 + random number(16-bytes)

Recognizes hash value
Response to command
Recognizes the
response to thecommand
Prepares thecommand

Recognizes the
response to thecommand
Prepares thecommand

Executes command
Sending (Hash value*) + command*Omit this option.

Generates hash value
from random
numbers + password

Recognizes the
response to thecommandSending (Hash value*) + command*Omit this option.

Terminates the connection・・・

Generates random number

Prepares thecommand(16-bytes)

Sending controller-generated
random number + hash value +command

30 seconds or less

Response to command(4-bytes)

Recognizes PJLINK 1

Response to command
Sending (controller-generated
random number, hash value*)+ command * Commands canbe omitted.

Generates a digest
Executes command
30 seconds or less

30 seconds or less
Recognizes the
response to thecommand
Prepares thecommandConnection termination

Response to command
Sending (controller-generated
random number, hash value*)+ command * Commands canbe omitted.

Executes command
30 seconds or less・・・
Terminates the connection

Connection termination

25

Controller (SHA256), Projector/Display (MD5) With authentication

Controller

Projector/Display
Connection establishment

Connects to TCP

Sending PJLINK 1 + random number(4-bytes)

Generates random number

Behavior①
Controller

Projector/Display(4-bytes)
PJLINK 2

Recognizes PJLINK
Recognizes security level

PJLINK ERR1PJLINK 2

Behavior differs depending on
the projector/display (① to ⑦)

Recognizes that an undefined commandhas been sent and responds with an error.

Terminates the connection

Connects to TCPConnection termination
Connection establishment
Generates random number
Sending PJLINK 1 + random number

Generates a digest
from random
numbers +password

Recognizes the
response to thecommand
Prepares thecommand.

Terminates the connection(4-bytes)

Behavior②
Sending a digest + command
Response to command
Sending (Hash value*) + command*Omit this option.

PJLINK 2

Executes command
30 seconds or less

PJLINK ERR2

・・・
Connection termination

Projector/Display

Controller
Recognizes hash value

Recognizes that the command is out of theparameter range and responds with an error.

Behavior
Controller

Projector/Display
PJLINK 2

PJLINK ERRA

Recognizes a password mismatchand responds with an error

26

Behavior⑦

Behavior④
Controller

Projector/Display

Controller

Projector/Display
PJLINK 2

PJLINK 2

PJLINK 2

Response to the received commandas it isNo response

Behavior⑤
Controller

Projector/Display
PJLINK 2
Connection termination

Immediate disconnection

Behavior⑥
Projector/Display

Controller
PJLINK 2

30 seconds
Connection termination

Disconnection due to timeout［This is the last page］

27