Anthem MRX / AVM

Anthem MRX 540 / 740 / 1140 AV receivers and AVM 70 / 90 AV processors, controlled over IP. The driver speaks Anthem's ASCII control protocol — short text commands terminated by a semicolon (;) on the unit's IP-control port (default 14999). It gives you power, two kinds of volume control (percent and exact dB), input switching, listening / surround mode, tone and balance, ARC room-correction profiles, on-screen messages, streaming "now playing" metadata, and zone 2 routing on the multi-zone models.

Because the unit answers every query with its current state, GEM keeps the device's status in sync with the real hardware on a poll — so a volume change made on the front panel, an Anthem remote, or the Anthem app shows up in GEM within a poll cycle without you doing anything.

How GEM sees the unit

This driver represents one receiver's main zone as a single device — it does not create a GEM control zone of its own, and it does not act as a matrix or controller. To get a room-level volume slider, mute button, and source behavior, you bind the device to an AV zone (see Linking to an AV zone below). Zone 2, where the model supports it, is driven with a separate set of z2_* commands rather than a second GEM zone.

What's controlled

• Main-zone power on / off, plus live power-state read-back
• Volume two ways: a 0–100 percent value that drives the room slider, and an exact-dB value in 0.5 dB steps for precise calibration — each with up / down stepping
• Mute on / off / toggle (the receiver has a native toggle)
• Input selection by input number, plus input cycling
• Listening / surround mode by name (Stereo, AnthemLogic, Dolby Surround, DTS Neural:X, and more)
• Bass / treble tone and left / right balance
• ARC (Anthem Room Correction) — switch the active EQ and processing profile
• On-screen display: post a two-line message, show / hide the OSD, open / close the setup menu, and simulate front-panel / remote key presses
• Dolby dynamic-range and center-spread options
• 12 V trigger outputs 1–3
• Streaming "now playing" — track title, artist, album, and transport state from the built-in Networking Module, plus pause / stop
• Read-back of the incoming signal: video resolution, audio format, channel layout, bitrate, sample rate, and bit depth
• Zone 2 power, volume, mute, and input on the MRX 740 / 1140 and AVM 70 / 90
• Status polling (default every 30 s) that mirrors external changes back into GEM

Prerequisites

• An Anthem MRX or AVM on the LAN with IP control enabled (Setup → Network on the unit). Note the IP-control port — the factory default is 14999, but it is configurable on the unit.
• Recommended: enable Standby IP Control on the Anthem. Without it, the unit drops off the network in standby and a single power-on command can be ignored — over RS-232 the power-on has to be sent twice with a one-second gap. With Standby IP Control on, a single power_on works reliably. (GEM also asks the unit to turn this on for you on first connect — see the Enable Connected Standby on Connect option below.)

Setup

1. On the Anthem, open Setup → Network and enable IP control. Note the port (default 14999).
2. Optionally enable Standby IP Control so the unit can be powered on remotely in one command.
3. In GEM, open Devices, add a device, and choose the Anthem MRX / AVM driver. Set the Device IP field. TCP Port defaults to 14999 — leave it unless you changed the port on the unit.
4. Save. On connect, GEM asks the unit for its model, optionally turns on Connected Standby, then seeds power, volume, mute, input, listening mode, and the incoming-audio details. From then on it re-reads that state on every poll.

Linking to an AV zone

The receiver feeds volume and mute into an AV zone rather than appearing as its own controllable zone:

1. Open AV Zones and edit (or create) the zone for the room the receiver serves.
2. Set the Volume Device field to this Anthem device.
3. Save. From then on, the zone's volume slider and mute button drive the receiver, and whenever the receiver reports a new volume or mute state, GEM mirrors it back onto the zone.

note

Selecting an input on the receiver is a device command, not a zone source change. The Anthem's selected input is tracked separately from GEM's AV source routing — choosing a room's source on a touchpanel does not change the receiver's input on its own unless you wire the input command into that source's on-macro.

Volume: percent vs. dB

The Anthem exposes volume two different ways, and the difference matters when you calibrate a room:

• volume sends a 0–100 percent value straight through to the receiver. The room slider uses this. Anthem's own percent curve is non-linear — the unit owns the mapping, and the driver passes your percent through unchanged:

  GEM percent	Approx. level
  0%	−90 dB (effectively off)
  4%	−74 dB
  11%	−53 dB
  20%	−35 dB
  30%	−25 dB
  100%	+10 dB

  So a slider at 50% is not half-loudness — most of the usable listening range sits between roughly 11% and 40%.

• volume_db sets an exact dB value (and volume_db_up / volume_db_down step by 0.5 dB). Use this when you want repeatable, dB-accurate levels — for example a macro that always sets the theater to −20 dB.

tip

If the on-screen volume reads as a percentage but you want dB, set Master Volume Scale to dB on the unit (Setup → Preferences → Master Volume Scale), and drive levels with volume_db.

Attributes

Device — required

Attribute	Type	Description
ip	string	Receiver / processor LAN IP.

Device — optional

Attribute	Type	Default	Description
port	int	14999	Anthem IP-control TCP port. Change only if you re-mapped it on the unit.
status_interval	int	30000	Status poll interval, in milliseconds (minimum 5000).
enable_connected_standby	boolean	true	On first connect, asks the unit to enable Connected Standby so power-on works in a single command. Turn this off if you rely on the lower-power, non-network standby instead.

The driver also auto-populates state attributes on the device as the unit reports them — these are read-only status, not values you set by hand:

power_state, volume (percent), volume_db, mute_state, input, input_name, listening_mode, audio_format, audio_channels, audio_bitrate, audio_sample_rate, audio_bit_depth, video_resolution, balance, model, software_version, hardware_version, serial_number, region, input_count, connected_standby, arc_valid, arc_name, arc_date, and the streaming fields stream_title, stream_artist, stream_album, stream_state, stream_service. The zone-2 equivalents appear with a z2_ prefix (z2_power_state, z2_volume, z2_mute_state, z2_input, …).

Commands

The exact protocol string each command sends is shown so you can match it against Anthem's control reference. Where a command takes a value, the argument name is the one you supply in a macro.

Power, volume, and mute (main zone)

Command	Sends	Notes
power_on	Z1POW1	Main-zone power on.
power_off	Z1POW0	Main-zone power off.
get_power	Z1POW?	Query power state.
volume	Z1PVOL + value	Set percent (0–100). Drives the room slider; non-linear (see above).
volume_up / volume_down	Z1PVUP / Z1PVDN	Step the percent volume up / down.
volume_db	Z1VOL + value	Set exact dB.
volume_db_up / volume_db_down	Z1VUP / Z1VDN	Step by 0.5 dB.
get_volume / get_volume_db	Z1PVOL? / Z1VOL?	Query percent / dB volume.
mute_on / mute_off	Z1MUT1 / Z1MUT0	Mute / unmute.
mute_toggle	Z1MUTt	Native toggle.
get_mute	Z1MUT?	Query mute state.

Input and listening mode

Command	Sends	Notes
input	Z1INP + value	Select input by number.
get_input	Z1INP?	Query selected input.
get_input_count	ICN?	How many inputs the unit exposes.
listening_mode	Z1ALM + value	Set surround / listening mode by name (table below).
listening_mode_up / listening_mode_down	Z1AUP / Z1ADN	Cycle modes.
get_listening_mode	Z1ALM?	Query current mode.

listening_mode accepts these names: none, anthemlogic_cinema, anthemlogic_music, dolby_surround, dts_neural_x, dts_virtual_x, stereo, all_channel_stereo, mono, all_channel_mono.

Tone and balance

Command	Sends	Notes
tone_bass / tone_treble	Z1TON0 / Z1TON1 + value	Set bass / treble level.
tone_bass_up / tone_bass_down	Z1TUP0 / Z1TDN0	Step bass.
tone_treble_up / tone_treble_down	Z1TUP1 / Z1TDN1	Step treble.
balance	Z1BAL + value	Set left / right balance.
balance_left / balance_right	Z1BLT / Z1BRT	Nudge balance one step.

ARC room correction

Command	Sends	Notes
arc_mode_eq	Z1ARCMEN + value	Active ARC EQ profile: disabled, profile_1…profile_4.
arc_mode_processing	Z1ARCPRC + value	ARC processing profile: disabled, profile_1…profile_4.
arc_chirp_offset	Z1ARCCLO + value	Calibration chirp offset.
arc_test_tone	Z1ARCCRP + value	Play the ARC test tone (channel bitmask).
get_arc_valid / get_arc_date / get_arc_name	Z1ARCVAL? / Z1ARCUPL? / Z1ARCNAM?	Whether a measurement is loaded, its upload date, and its name.

Surround features

Command	Sends	Notes
dolby_dynamic_range	Z1DYN + value	normal, reduced, or late_night.
dolby_surround_center_spread	Z1DSCS + value	on / off.

Signal read-back (status only)

get_video_resolution (Z1VIR?), get_audio_channels (Z1AIC?), get_audio_format (Z1AIF?), get_audio_bitrate (Z1BRT?), get_audio_sample_rate (Z1SRT?), get_audio_bit_depth (Z1BDP?), get_input_name (Z1AIN?), and get_input_rate_name (Z1AIR?) read what's currently arriving at the selected input. These populate the matching state attributes; they don't change anything.

On-screen display and front panel

Command	Sends	Notes
osd_message	Z1MSG + row + message	Post a message to a screen row.
osd_show / osd_hide	Z1SHC1 / Z1SHC0	Show / hide the on-screen display.
setup_menu_open / setup_menu_close / setup_menu_toggle	Z1SMD1 / Z1SMD0 / Z1SMDt	Drive the setup menu.
simulate_ir	Z1SIM + key	Simulate a front-panel / remote key press.

12 V triggers

Command	Sends	Notes
trigger_on	R{n}SET1	Assert trigger n (1, 2, or 3).
trigger_off	R{n}SET0	De-assert trigger n (1, 2, or 3).

note

For the trigger commands to do anything, the corresponding 12 V trigger on the unit must be set to RS-232 / IP control mode in the Anthem's trigger setup. A trigger left on "source"/"voltage"-follow mode ignores them.

Streaming (Networking Module)

Command	Sends	Notes
get_stream_title / get_stream_artist / get_stream_album	NMTI? / NMAR? / NMAL?	Now-playing metadata.
get_stream_state	NMTE?	stopped, transitioning, paused, or playing.
streaming_pause / streaming_stop	NMPC / NMSC	Transport control for the built-in streamer.

System and identity

Command	Sends	Notes
get_model / get_firmware / get_serial	IDM? / IDS? / GSN	Identity read-back.
get_region / get_build_date / get_hardware / get_identity	IDR? / IDB? / IDH? / IDQ?	More identity fields.
set_connected_standby / get_connected_standby	GCCSTBY + value / GCCSTBY?	enabled / disabled.
load_user_settings / save_user_settings	CPYS10 / CPYS01	Recall / store a user-settings snapshot.
load_factory_defaults	LDFDS	Reset the unit to factory defaults.

Zone 2 (MRX 740 / 1140, AVM 70 / 90 only)

z2_power_on / z2_power_off / z2_get_power, z2_mute_on / z2_mute_off / z2_mute_toggle / z2_get_mute, z2_volume (percent) / z2_volume_db (dB) / z2_volume_up / z2_volume_down / z2_get_volume, and z2_input / z2_get_input. These mirror the main-zone commands onto the second zone. On single-zone models the unit answers them with a "zone off" error and nothing happens.

Known limitations and quirks

• Percent volume is non-linear. The room slider follows Anthem's own percent curve (table above), so 50% is not half-loud. Use volume_db wherever you need repeatable, dB-accurate levels.
• Listening-mode numbers can shift between firmware revisions. Anthem's published table has a duplicate entry, and the driver assumes stereo = 6. If you script a specific mode by name and the unit lands on the wrong one, confirm the mapping on your firmware and adjust.
• Most commands need the unit out of standby. While powered off (but networked), the unit only honors model and power queries and the power commands; other commands return a "zone off" error, which the driver tolerates and logs. Power the unit on first if a command seems to do nothing in standby.
• Some queries don't exist on every model. If the unit reports a command as unrecognized, the driver stops polling that one for the rest of the session rather than spamming the log — reload the device to re-test after a firmware update.
• Bulk setting changes trigger a re-read. After you load user settings or factory defaults, the unit announces a bulk change and the driver re-runs its full status sweep so GEM catches up.

Troubleshooting

Symptom	Check
Power-on is sometimes ignored	Enable Standby IP Control on the unit (or leave Enable Connected Standby on Connect turned on). Without it, the unit leaves the network in standby and the first power-on can be dropped.
Volume slider shows %, the unit shows dB (or vice versa)	Set Master Volume Scale on the Anthem (Setup → Preferences → Master Volume Scale) to match, or drive levels with volume_db for exact dB.
No response at all	Confirm IP control is enabled on the unit and the TCP Port matches (default 14999). Make sure the IP is correct and reachable on the LAN.
A command is rejected	The Anthem replies with a short error code the driver logs: unrecognized command, value out of range, invalid syntax, or "zone off" (the unit is in standby, or it's a zone-2 command on a single-zone model). Power the unit on, check the value range, or confirm the model supports the feature.
Zone 2 commands do nothing	Zone 2 exists only on the MRX 740 / 1140 and AVM 70 / 90. On other models the unit answers with a "zone off" error.

See also

• Denon Receiver, Marantz Receiver, Onkyo Receiver, Pioneer VSX / Elite Receiver — other residential AV receivers, each bound to an AV zone the same way.
• AV Zones — set this receiver as a zone's Volume Device.
• AV Sources — how room sources route, and where an input-switch macro would live.