Projector RS232 Commands: Complete Reference by Brand

Every Projector Brand Does This Differently

There is no shared convention for projector serial control. Nine protocols, nine framing styles, and the only thing they have in common is that a wrong byte produces silence rather than an error.

This page is the index. Each brand links to a full reference with the complete command set, pinout, serial settings and the failure modes specific to that brand.

Power On, All Nine Protocols

Every byte sequence below was computed and verified rather than copied from a table.

Note how little these have in common. Three are pure ASCII text, two are pure binary, one wraps text in framing bytes, one requires quotes around its parameter, and one needs a carriage return at both ends.

Displays are a separate world again — see Samsung MDC, Samsung Ex-Link and LG.

Decide This First: PJLink or Native?

Before looking up any brand-specific command, answer this — it determines how much work the whole job is.

PJLink is a cross-brand standard supported by most business and installation projectors from Epson, Panasonic, NEC, Sony, Christie, Barco, BenQ and Optoma. One command set, over the network, for all of them.

The practical pattern for a mixed hall: PJLink for the common operations, native protocol for the handful of brand-specific things you actually need. That usually means one PJLink implementation plus two or three native commands, rather than four complete native implementations.

The Three Things That Break Regardless of Brand

Whichever protocol you land on, the same three categories account for nearly every failure.

1. The physical layer

Almost every projector needs a null modem (crossover) cable — pins 2 and 3 swapped, plus ground. Straight-through cables are what ship in boxes and what you find in the bag, which makes this the highest-frequency failure in commissioning.

Some models add requirements: Panasonic may need pins 7-8 (RTS/CTS) linked at the projector end, and without it the projector silently discards everything.

→ RS232 null modem vs straight-through

2. The command format

Terminators differ (CR / LF / CR+LF / STX-ETX / none). Some protocols are ASCII text, some are raw bytes, and 01 means 0x30 0x31 in one and 0x01 in another. Checksums use four different rules across common gear.

→ Terminators, ASCII vs HEX and checksums

3. Standby power mode

The single most common operational symptom in exhibition work: power off works, power on never does.

In deep eco standby the projector powers down its serial and network receiver, so nothing is listening for the wake command. Every brand has a setting for this, under a different name.

Related timing rules, all brand-specific:

• NEC refuses all commands during the cooling period

• Panasonic has a 10–60 second blackout after the lamp strikes

• Barco wants 30 seconds after power-up completes

• Epson accepts only a small subset of commands in standby, returning ERR for the rest

How to Bring Up a Projector

The order that wastes the least time:

1. Enable serial control in the projector's menu. Many models ship with it off, or with LAN control taking precedence. Optoma requires a remote-key sequence; Epson needs RS-232C selected under Advanced.

2. Connect a laptop with a terminal — not the control system. This proves the device independently. PuTTY cannot send binary, so use Hercules or RealTerm for NEC and Panasonic.

3. Send the cheapest possible message first. A bare CR on Epson should return :. A malformed command on BenQ returns Illegal format. An error reply is a success — it proves cable, baud rate, parity and framing all reached the parser.

4. Then power on, then power off, tested separately. Power off working proves nothing about power on.

5. Switch inputs by hand and query the device to record the real input values. Published input tables are model-specific and frequently wrong.

6. Only now move the verified commands into the control system.

→ Full commissioning checklist

What the Reply Tells You

Brands that explain their refusals, and what they mean:

BenQ's three-way distinction is the most useful in the industry, and Panasonic's echo is the most dangerous — naive control systems read "bytes came back" as success while the projector sits dark.

Network Control

Several of these protocols work identically over TCP, which is usually the better end state: no serial cable, no crossover question, no COM port assignment.

Commission over serial where you can see everything, then move to the network for the permanent run.

Full References

Projectors
PJLink · Epson · Panasonic · Sony · NEC · Christie / Barco / Optoma / BenQ

Displays
Samsung MDC · Samsung Ex-Link · LG

Cross-cutting
Command format · Cabling · Terminal software · Serial fundamentals · All AV protocols

Related systems
Modbus for building devices · Wake-on-LAN · Art-Net vs sACN lighting · Dante audio

Process
Commissioning checklist · Third-party TCP integration

With SoftControl

SoftControl speaks all nine protocols above — serial, TCP, UDP, HTTP, PJLink — with text and hex payloads, so the ASCII brands and the binary brands live in the same interface and the same macro.

Its command tester shows the request as text, bytes and hex alongside the raw reply, which is what makes the step-3 verification above quick, and what distinguishes a genuine acknowledgement from Panasonic's standby echo.

For centrally controlling many projectors at once, see the projector centralized control guide.