Hope this can help people. I suspect many codes can be used across different models.
| DENON X4400H Serial tp IP codes | Network |
|---|---|
| Power ON | PWON\x0D |
| Power Standby | PWSTANDBY\x0D |
| Master Volume Up | MVUP\x0D |
| Master Volume Down | MVDOWN\x0D |
| Left Font Channel Volume Up | CVFL UP\x0D |
| Left Front Channel Volume Down | CVFL DOWN\x0D |
| Right Front Channel Volume Up | CVFR UP\x0D |
| Right Front Channel Volume Down | CVFR DOWN\x0D |
| Center Channel Volume Up | CVC UP\x0D |
| Center Channel Volume Down | CVC DOWN\x0D |
| Subwoofer Cannel Volume Up | CVSW UP\x0D |
| Subwoofer Channel Volume Down | CVSW DOWN\x0D |
| Surrond Left Channel Volume Up | CVSL UP\x0D |
| Surround Left Channel Volume Down | CVSL DOWN\x0D |
| Surround Right Channel Volume Up | CVSR UP\x0D |
| Surrond Right Channel Volume Down | CVSR DOWN\x0D |
| Surround Back Left Channel Volume Up | CVSBL UP\x0D |
| Surround Back Left Channel Down | CVSBL DOWN\x0D |
| Surround Back Right Channel Volume Up | CVSBR UP\x0D |
| Surround Back Right Volume Down | CVSBR DOWN\x0D |
| Mute On | MUON\x0D |
| Mute Off | MUOFF\x0D |
| Select Input PHONO | SIPHONO\x0D |
| Select Input CD | SICD\x0D |
| Select Input TUNER | SITUNER\x0D |
| Select Input DVD | SIDVD\x0D |
| Select Input BLURAY | SIBD\x0D |
| select Input TV | SITV\x0D |
| Select Input SAT/CBL | SISAT/CBL\x0D |
| Select Input MEDIAPLAYER | SIMPLAY\x0D |
| Select Input GAME | SIGAME\x0D |
| Select Input AUX1 | SIAUX1\x0D |
| Select Input AUX2 | SIAUX2\x0D |
| Select Input NET | SINET\x0D |
| Select Input SPOTIFY | SISPOTIFY\x0D |
| Select Input FLICKR | SIFLICKR\x0D |
| Select Input FAVORITES | SIFAVORITES\x0D |
| Select Input IRADIO | SIIRADIO\x0D |
| Select Input SERVER | SISERVER\x0D |
| Select Input USB/IPOD | SIUSB/IPOD\x0D |
| Select Input Source USBPLAY | SIUSB\x0D |
| Select Input Source iPODPLAY | SIIPD\x0D |
| Select Input Source IRADIOPLAY | SIIRP\x0D |
| Select Input Source FAVORITESPLAY | SIFVP\x0D |
| Input Change Set Auto | SDAUTO\x0D |
| Input Change Set HDMI | SDHDMI\x0D |
| Input Change Set DIGITAL | SDDIGITAL\x0D |
| Input Change Set ANALOG | SDANALOG\x0D |
| Digital Input Set AUTO | DCAUTO\x0D |
| Digital Input Set PCM | DCPCM\x0D |
| Digital Input Set DTS | DCDTS\x0D |
| Video Select MODE ON | SVON\x0D |
| Video Select MODE CANCEL | SVOFF\x0D |
| Video Select set DVD | SVDVD\x0D |
| Video Select set BD | SVBD\x0D |
| Video Select set TV | SVTV\x0D |
| Video Select set SAT/CBL | SVSAT/CBL\x0D |
| Video Select set MEDIAPLAY | SVMPLAY\x0D |
| Video Select set GAME | SVGAME\x0D |
| Video Select set AUX1 | SVAUX1\x0D |
| Video Select set AUX2 | SVAUX2\x0D |
| SVAUX2\x0D | SVCD\x0D |
| Select SURROUND MOVIE | MSMOVIE\x0D |
| Select SURROUND MUSIC | MSMUSIC\x0D |
| Select SURROUND GAME | MSGAME\x0D |
| Select SURROUND Pure Direct | MSPURE DIRECT\x0D |
| Select SURROUND Direct | MSDIRECT\x0D |
| Select SURROUND Stereo | MSSTEREO\x0D |
| Select SURROUND Standard | MSSTANDARD\x0D |
| Select SURROUND Dolby Digital | MSDOLBY DIGITAL\x0D |
| Select SURROUND DTS Surround | MSDTS SURROUND\x0D |
| Select SURROUND MULTI CH Stereo | MSMCH STEREO\x0D |
| Select SURROUND Rock Arena | MSROCK ARENA\x0D |
| Select SURROUND Jazz Club | MSJAZZ CLUB\x0D |
| Select SURROUND Mono Movie | MSMONO MOVIE\x0D |
| Select SURROUND Matrix | MSMATRIX\x0D |
| Select SURROUND Video Game | MSVIDEO GAME\x0D |
| Select SURROUND Virtual | MSVIRTUAL\x0D |
| Select SURROUND QUICK1 | MSQUICK1\x0D |
| Select SURROUND QUICK2 | MSQUICK2\x0D |
| Select SURROUND QUICK3 | MSQUICK3\x0D |
| Select SURROUND QUICK1 MEMORY | Select SURROUND QUICK1 MEMORY |
| Select SURROUND QUICK1 MEMORY | MSQUICK2 MEMORY\x0D |
| Select SURROUND QUICK3 MEMORY | MSQUICK3 MEMORY\x0D |
| Video Aspect Ratio 4:3 Mode | VSASPNRM\x0D |
| Video Aspect Ratio 16:9 Mode | VSASPFUL\x0D |
| Video Resolution set 480p | VSSC48P\x0D |
| Video Resolution set 1080i | VSSC10I\x0D |
| Video Resolution set 720p | VSSC72P\x0D |
| Video Resolution set 1080p | VSSC10P\x0D |
| Video Resolution Set 1080p/24 | VSSC10P24\x0D |
| Video Resolution Set 4K | VSSC4K\x0D |
| Video Resolution Set AUTO | VSSCAUTO\x0D |
| Video Resolution Set 480p HDMI | VSSCH48P\x0D |
| Video Resolution Set 1080i HDMI | VSSCH10I\x0D |
| Video Resolution Set 720p HDMI | VSSCH72p\x0D |
| Video Resolution Set 1080p HDMI | VSSCH10P\x0D |
| Video Resolution Set 1080p/24 HDMI | VSSCH10P24\x0D |
| Video Resolution Set 4K HDMI | VSSCH4K\x0D |
| Video Resolution Set AUTO HDMI | VSSCHAUTO\x0D |
| HDMI Audio Out to AMP | VSAUDIO AMP\x0D |
| HDMI Audio Out to TV | VSAUDIO TV\x0D |
| Video Processing Mode to AUTO | VSVPMAUTO\x0D |
| Video Processing Mode to GAME | VSVPMGAME\x0D |
| Video Processing Mode to MOVIE | VSVPMMOVI\x0D |
| PARAMETER SOUND Tone Control ON | PSTONE CTRL ON\x0D |
| PARAMETER SOUND Tone Control OFF | PSTONE CTRL OFF\x0D |
| PARAMETER SOUND CINEMA EQ. ON | PSCINEMA EQ.ON\x0D |
| PARAMETER SOUND CINEMA EQ.OFF | PSCINEMA EQ:OFF\x0D |
| PARAMETER SOUND MODE:MUSIC | PSMODE:MUSIC |
| PARAMETER SOUND MODE:CINEMA | PSMODE:CINEMA\x0d |
| PARAMETER SOUND MODE:GAME | PSMODE:GAME\x0D |
| PARAMETER SOUND Loudness Managment ON | PSLOM ON\x0D |
| PARAMETER SOUND Loudness Managment OFF | PSLOM OFF\x0D |
| PARAMETER SOUND PL IIz Height Gain LOW | PSPHG LOW\x0D |
| PARAMETER SOUND PL IIz Height Gain MID | PARAMETER SOUND PL IIz Height Gain MID |
| PARAMETER SOUND PL IIz Height Gain HIGH | PSPHG HI\x0D |
| Parameter Sound MultiEQ AUDYSSEY | PSMULTEQ:AUDYSSEY\x0D |
| Parameter Sound MultiEQ BYP L/R | PSMULTEQ:BYP.LR\x0D |
| Parameter Sound MultiEQ Manual | PSMULTEQ:MANUAL\x0D |
| Parameter Sound MultiEQ Flat | PSMULTEQ:FLAT\x0D |
| Parameter Sound MultiEQ Off | PSMULTEQ:OFF\x0D |
| PARAMETER SOUND BASS UP | PSBAS UP\x0D |
| PARAMETER SOUND BASS DOWN | PSBAS DOWN\x0D |
| PARAMETER SOUND TREBLE UP | PSTRE UP\x0DE |
| PARAMETER SOUND TREBLE DOWN | PSTRE DOWN\x0 |
| PARAMETER SOUND DRC AUTO | PSDRC AUTO\x0D |
| PARAMETER SOUND DRC LOW | PSDRC LOW\x0D |
| PARAMETER SOUND DRC MID | PSDRC MID\x0D |
| PARAMETER SOUND DRC HI | PSDRC HI\x0D |
| PARAMETER SOUND DRC OFF | PSDRC OFF\x0D |
| PARAMETER SOUND LFE UP | PSLFE UP\x0D |
| PARAMETER SOUND LFE DOWN | PSLFE DOWN\x0D |
| PARAMETER SOUND EFFECT UP | PSEFF UP\x0D |
| PARAMETER SOUND EFFECT DOWN | PSEFF DOWN\x0D |
| PARAMETER SOUND DELAY UP | PSDEL UP\x0D |
| PARAMETER SOUND DELAY DOWN | PSDEL DOWN\x0D |
| PARAMETER SOUND PANORAMA ON | PSPAN ON\x0D |
| PARAMETER SOUND PANORAMA OFF | PSPAN OFF\x0D |
| PARAMETER SOUND DIMENSION UP | PSDIM UP\x0D |
| PARAMETER SOUND DIMENSION DOWN | PSDIM DOWN\x0D |
| PARAMETER SOUND CENTER WIDTH UP | PSCEN UP\x0D |
| PARAMETER SOUND CENTER WIDTH DOWN | PSCEN DOWN\x0D |
| PARAMETER SOUND SubWoofer ON | PSSWR ON\x0D |
| PARAMETER SOUND SubWoofer OFF | PSSWR OFF\x0D |
| PARAMETER SOUND ROOM SIZE S | PSRSZ S\x0D |
| PARAMETER SOUND ROOM SIZE MS | PSRSZ MS\x0D |
| PARAMETER SOUND ROOM SIZE M | PSRSZ M\x0D |
| PARAMETER SOUND ROOM SIZE ML | PSRSZ ML\x0D |
| PARAMETER SOUND ROOM SIZE L | PSRSZ L\x0D |
| PARAMETER SOUND AUDIO DELAY UP | PSDELAY UP\x0D |
| PARAMETER SOUND AUDIO DELAY DOWN | PSDELAY DOWN\x0D |
| PARAMETER SOUND AUDIO RESTORER OFF | PSRSTR OFF\x0D |
| PARAMETER SOUND AUDIO RESTORER LOW | PSRSTR LOW\x0D |
| PARAMETER SOUND AUDIO RESTORER MEDIUM | PSRSTR MED\x0D |
| PARAMETER SOUND AUDIO RESTORER HIGH | PSRSTR HI\x0D |
| PARAMETER VIDEO PICTURE MODE=OFF | PVOFF\x0D |
| PARAMETER VIDEO PICTURE MODE=STANDARD | PVSTD\x0D |
| PARAMETER VIDEO PICTURE MODE=MOVIE | PVMOV\x0D |
| PARAMETER VIDEO PICTURE MODE=VIVID | PVVVD\x0D |
| PARAMETER VIDEO PICTURE MODE=STREAM | PVSTM\x0D |
| PARAMETER VIDEO PICTURE MODE=CUSTOM | PVCTM\x0D |
| PARAMETER VIDEO CONTRAST UP | PVCN UP\x0D |
| PARAMETER VIDEO CONTRAST DOWN | PVCN DOWN\x0D |
| PARAMETER VIDEO BRIGHTNESS UP | PVBR UP\x0D |
| PARAMETER VIDEO BRIGHTNESS DOWN | PVBR DOWN\x0D |
| PARAMETER VIDEO SATURATION UP | PVST UP\x0D |
| PARAMETER VIDEO SATURATION DOWN | PVST DOWN\x0D |
| PARAMETER VIDEO HUE UP | PVHUE UP\x0D |
| PARAMETER VIDEO HUE DOWN | PVHUE DOWN\x0D |
| PARAMETER VIDEO DNR OFF | PVDNR OFF\x0D |
| PARAMETER VIDEO DNR LOW | PVDNR LOW\x0D |
| PARAMETER VIDEO DNR MID | PVDNR MID\x0D |
| PARAMETER VIDEO DNR HIGH | PVDNR HI\x0D |
| PARAMETER VIDEO ENHANCER UP | PVENH UP\x0D |
| PARAMETER VIDEO ENHANCER DOWN | PVENH DOWN\x0D |
| PARAMETER SOUND Cinema EQ : ON | PSCINEMA EQ.ON\x0D |
| PARAMETER SOUND Cinema EQ :OFF | PSCINEMA EQ.OFF\x0D |
| PARAMETER SOUND Dynamic EQ : ON | PSDYNEQ ON\x0D |
| PARAMETER SOUND Dynamic EQ : OFF | PSDYNEQ OFF\x0D |
| Preview ON | MNPRV ON\x0D |
| Preview OFF | MNPRV OFF\x0D |
| Cursor UP | MNCUP\x0D |
| Cursor Down | MNCDN\x0D |
| Cursor Left | MNCLT\x0D |
| Cursor Right | MNCRT\x0D |
| Enter | MNENT\x0D |
| Return | MNRTN\x0D |
| Option | MNOPT\x0D |
| Info | MNINF\x0D |
| Menue On | MNMEN ON\x0D |
| Menue Off | MNMEN OFF\x0D |
| Trigger 1_On | TR1 ON\x0D |
| Trigger 1_Off | TR1 OFF\x0D |
| Trigger 2_On | TR2 ON\x0D |
| Trigger 2_Off | TR2 OFF\x0d |
| VOLUME REQUEST | MV?\x0D |
| Input Request | SI?\x0D |
| Trigger Status | TR?\x0D |
| Front Right Request | FR?\x0D |
| Front Left Request | FL?\x0D |
| Center Volume Request | C?\x0D |
| Surround Left Request | SL?\x0D |
| Surround Right Request | SR?\x0D |
| Surround Back Left Request | SBL?\x0D |
| Surround Back Right Request | SBR?\x0D |
| Dyn.EQ Request | PSDYNEQ ?\x0D |
| Audio Restorer Request | PSRSTR ?\x0D |
| Cinema EQ Request | PSCINEMA EQ. ?\x0D |
| Surround Mode Request | MS?\x0D |
| MultiEQ Request | PSMULTEQ: ?\x0D |
| DNR Request | PVDNR ?\x0D |
| Video Process Request | VSVPM ?\x0D |
| Picture Mode Request | PV?\x0D |
| Video Resulotion Request | VSSCH ?\x0D |
| Video Aspect Request | VSASP ?\x0D |