Panasonic Projector RS232 Commands: STX/ETX Framing, PON and the ID Prefix

The Frame: Everything Lives Between STX and ETX

Panasonic wraps every command in two control bytes. This is the single fact that determines whether your commands work:

STX  command  ETX
0x02   PON    0x03

The full byte sequence for power on:

Hex      : 02 50 4F 4E 03
Decimal  : 2 80 79 78 3
Escaped  : "\x02PON\x03"

STX and ETX are raw bytes, not text. If you type the literal characters S, T, X into a terminal you will send three ASCII letters and the projector will ignore the whole frame. Send 0x02 and 0x03 as binary. In most debugging tools this means switching the send mode to HEX, or using an escape syntax like \x02.

The command body is three characters (C1 C2 C3), ASCII, case-sensitive — upper-case PON is not the same as pon. If the command takes parameters, they follow a colon:

STX  C1C2C3 : P1..P4  ETX
0x02  IIS   :  HD1    0x03

When a command takes no parameters, the colon is omitted entirely. Sending PON: with a trailing colon is a malformed frame.

The ID Prefix Variant

Larger PT-D / PT-R series projectors — the ones designed to be daisy-chained — use an extra ID field inside the frame:

STX  ID  ;  command  ETX

The documented power-on string in this form is ADZZ;PON:

Hex : 02 41 44 5A 5A 3B 50 4F 4E 03

AD identifies the addressing scheme and ZZ is the broadcast ID — every projector on the chain responds. To address one unit you replace ZZ with its assigned ID.

Which variant your projector uses is a per-model fact, not a per-series one. Check the RS-232C specification sheet for your exact model before assuming. Sending the plain PON frame to a projector expecting the ID form (or vice versa) produces exactly the same symptom as a dead cable: nothing happens.

Wiring and the Pins 7-8 Jumper

Panasonic uses a 9-pin D-sub on most installation projectors, with a null-modem (crossover) connection to a PC. Some compact models use an 8-pin DIN connector instead and need Panasonic's own adapter — no amount of cable-swapping will help there.

The gotcha that costs the most time: several models require pins 7 and 8 (RTS/CTS) to be linked together at the projector end. Without that jumper the projector never asserts clear-to-send and silently discards everything you transmit. The cable looks fine, the pinout looks fine, and nothing works.

If you are troubleshooting a Panasonic that ignores every command and you have already checked baud rate and framing, check for the 7-8 link before you check anything else.

Serial Settings

Command Reference

Byte sequences for the three you will use most:

PON  →  02 50 4F 4E 03
POF  →  02 50 4F 46 03
QPW  →  02 51 50 57 03

OSH deserves a mention for exhibition work. Panasonic installation projectors have a mechanical shutter, and closing it between visitor groups is far better than power cycling — instant, silent, and it does not consume a lamp/laser start cycle or force a cooling wait.

Timing Rules You Must Respect

Panasonic's specification is unusually explicit about timing, and ignoring it is the second most common failure after the pins 7-8 jumper.

1. There is a blackout window after the lamp strikes.
No command may be sent or received for 10 to 60 seconds after the lamp starts lighting. A control system that sends PON and then immediately sends IIS to select the input will have that second command vanish. Build the delay into your macro.

2. Wait for the response before sending the next command.
Do not pipeline. Send, wait, then send.

3. Set your timeout to 10 seconds or more.
Panasonic projectors can legitimately take that long to answer during state transitions. A 2-second timeout will report failures that are not failures.

Why Your Panasonic Command Gets No Response

1. The pins 7-8 jumper is missing. See above. This is the one.

2. You sent the literal text "STX". Send 0x02 / 0x03 as bytes.

3. Wrong frame variant. Plain PON to an ID-expecting model, or ADZZ;PON to one that wants the plain form.

4. You are inside the 10-60 second lamp-ignition window. The command was genuinely discarded by the projector.

5. Straight-through cable instead of null-modem. Or an 8-pin DIN model without the correct adapter.

6. The projector echoed your command and you read it as success.
This one deserves its own section.

The Standby Echo That Fakes Success

When a Panasonic projector receives a command while in standby, it returns the received command unchanged.

Send PON in standby and you may get PON back. A naive control system sees bytes arrive, treats "got a response" as "command succeeded", and reports the projector as powered on — while it sits there dark.

The fix is to never trust the echo. Verify with QPW. After sending PON, wait, then query the power state and check the value. This is the correct pattern for any unattended installation, and it is why the Panasonic spec bothers to document QPW as the confirmation method for power operations.

If you are debugging and see your own command coming back at you, that is not a loopback in your cable — it is the projector telling you it is in standby and not accepting that command.

With SoftControl

SoftControl sends Panasonic frames as raw bytes over serial or TCP, so 0x02 and 0x03 go out as control bytes rather than text. Its command tester displays the exact hex sent and the raw bytes returned — which is how you tell a genuine acknowledgement apart from the standby echo described above, instead of discovering the difference on opening day.

For the cross-brand view see the projector control guide, for network control of mixed-brand halls see PJLink, and for RS-232/485 fundamentals see the serial communication guide.