KramerRS-232Matrix SwitcherProtocol 3000Crestron

Kramer Switcher RS-232 Commands: Protocol 2000 and Protocol 3000 Guide

May 1, 2026

Kramer switchers use two completely different RS-232 protocols depending on generation — Protocol 2000 (binary HEX, older) and Protocol 3000 (ASCII, newer). Using the wrong protocol results in no response.


How to Tell Which Protocol Your Device Uses

Protocol 3000 (ASCII): Used on most Kramer products from ~2010 onwards. The manual shows commands like ROUTE, INFO, or MODEL. Baud rate is typically 115200.

Protocol 2000 (HEX): Used on older matrix switchers. The manual shows HEX byte tables. Baud rate is typically 9600.


Protocol 3000 — Serial Port Settings

ParameterValue
Baud Rate**115200**
Data Bits8
ParityNone
Stop Bits1
TerminatorCR (0x0D)

Protocol 3000 — Commands

FunctionCommand
Route Input 1 to Output 1 (video)`#ROUTE 1,1,1 + CR`
Route Input 2 to Output 3 (video)`#ROUTE 1,3,2 + CR`
Query routing`#ROUTE? 1,1 + CR`
Device info`#INFO + CR`
Lock front panel`#LOCK-FP 1 + CR`

Format: #ROUTE Layer,Output,Input where Layer 1 = video, Layer 2 = audio.


Protocol 2000 — Serial Port Settings

ParameterValue
Baud Rate9600
Data Bits8
ParityNone
Stop Bits1

Protocol 2000 — Commands (HEX)

FunctionHEX Bytes
Route Video In1 to Out1`01 01 01 81`
Route Video In2 to Out3`01 02 03 81`
Route Video In1 to All`01 01 00 81`

Crestron SIMPL+ — Protocol 3000

```

STRING_PARAMETER SP_Route_1_1[14] = "#ROUTE 1,1,1\x0D";

STRING_PARAMETER SP_Route_2_1[14] = "#ROUTE 1,1,2\x0D";

STRING_PARAMETER SP_Info[8] = "#INFO \x0D";

DIGITAL_INPUT Input1, Input2;

STRING_OUTPUT TX$;

PUSH Input1 { TX$ = SP_Route_1_1; }

PUSH Input2 { TX$ = SP_Route_2_1; }

```

Set COM port to 115200 baud for Protocol 3000.


Common Mistakes

  • Wrong baud rate — Protocol 3000 uses 115200, not 9600. This is the most common mistake
  • Wrong protocol for device — check the manual before writing code
  • Missing layer parameter in ROUTE command — Layer 1 = video, Layer 2 = audio

Related Guides


Free RS-232 Tools

Baud rate reference, device settings table, terminator guide, and DB9 pinout — all free, no signup required.

Open Free RS-232 Tools →


Generate RS-232 Commands Instantly

Need exact command strings for a device not covered here? [AV-Command](https://av-command.com) includes free RS-232 troubleshooting checklists and a free tools reference — no signup required. The AI Assistant generates exact command strings, serial port settings, and Crestron SIMPL+ code for hundreds of devices instantly.

Try AV-Command Free — upgrade anytime for AI commands →

⚡ AV-Command Pro
Need commands for a different device?
AV-Command generates RS-232 command strings, serial port settings, and Crestron SIMPL+ code for hundreds of AV devices instantly.
Get Pro Access — $5.99/mo →