RTI AD-4x / AD-8x (TCP)

Driver: rti_ad8

Multi-zone audio control for the RTI AD-4x and AD-8x audio distribution amplifiers over the amp's native TCP control port. Each amplifier output becomes a GEM zone with independent power, mute, volume, bass, treble, and input selection, and the driver polls every zone for its current state as soon as it connects.

This is the lower-overhead path and is the right default for most installs. There is also an HTTP variant — RTI AD-4x / AD-8x (HTTP) — that drives the same amplifier through its web interface on port 80. Pick the HTTP driver only if you see the amp's TCP control port stop responding after long uptime while the web UI keeps working; otherwise stay on this TCP driver.

What it does

• Per-zone power, mute, and volume, plus bass and treble tone control and physical-input selection.
• Global "all zones on / off" and "mute / unmute all" one-shot commands.
• On every connect, walks each configured zone and requests its status, so power, mute, and volume reflect the amp within a few seconds of coming online.
• Pushes live state changes back into GEM as the amp reports them — no polling interval to tune; the amp answers each status request and after each command.

Prerequisites

• An RTI AD-4x (4 outputs) or AD-8x (8 outputs) audio distribution amplifier on the LAN with IP/telnet control enabled.
• A reachable IP address for the amp. Reserve it on the router by DHCP or set it static so it does not move.
• TCP control port open — the factory default is 23.

Setup steps

1. Confirm the amp answers on its control port — from a machine on the same LAN, a telnet session to <amp-ip> on port 23 should connect.

2. Open Devices, add a new device, and choose the RTI AD-8x Audio Distribution driver (rti_ad8).

3. Enter the amp's IP Address. Leave TCP Port at 23 unless your amp was moved to a non-default port.

4. Add one Zone for each amplifier output you want to control. Set each zone's Address to the plain 1-based output number:

   • AD-4x → 1 through 4
   • AD-8x → 1 through 8

   Enter the number as-is (1, 2, …). GEM zero-pads it to two digits on the wire automatically — do not type 01.

5. Save and enable the device. On connect the driver requests status for every zone (about one second apart), so give a large system a few seconds to fully populate. After that, power/mute/volume changes made anywhere — GEM, a keypad, or the front panel — surface on the zone.

Placing the device

The amp lives in the AV subsystem, and each output zone belongs there too. Because the driver supports AV zones, you can also surface each output as an AV Zone to get the volume / mute / source controls on the AV pages and touchpanels.

Attribute reference

Device

Name	Required	Default	Description
ip	yes	—	LAN IP of the RTI amplifier.
port	no	23	TCP control port. Only change it if the amp was moved off the default.

The device also inherits the standard TCP tuning attributes (reconnect timing, command throttle, status/ping intervals). The defaults are correct for RTI hardware — leave them alone unless you are troubleshooting a specific timing problem.

Zone

No required zone attributes beyond the Address. Set the address to the 1-based output number (1-4 on AD-4x, 1-8 on AD-8x).

Reflected attributes (read-only)

The driver writes these onto each zone from the amp's status replies — after the connect-time sweep and after each command. You never set them by hand; they appear once the device is connected.

Target	Name	Type	Notes
Zone	power_state	string	on / off.
Zone	mute_state	string	on / off.
Zone	volume	int	0-100 (GEM scale).

Input is not reflected on the TCP driver

This TCP driver can set a zone's physical input (see set_input below) but does not report the current input back — the amp's status frame is not parsed for it here. GEM therefore will not show which input a zone is on when using rti_ad8. If tracking the live selected input matters for your install, the HTTP variant reflects it as a zone.input attribute.

Commands

All per-zone commands take the zone's address (the 1-based output number). GEM pads it to two digits before sending, so pass the plain number.

Command	Args	Notes
zone_on / zone_off	address	Power one output on or off.
power_toggle	address	Toggle one output's power.
mute_on / mute_off	address	Mute control for one output.
mute_toggle	address	Toggle mute for one output.
volume	address, volume	Set volume 0-100 (GEM scale); converted to the amp's dB range internally.
volume_up / volume_down	address	Step the volume up or down by one amp step.
set_bass	address, level	Bass tone control. Range follows the amp firmware.
set_treble	address, level	Treble tone control. Range follows the amp firmware.
set_input	address, input	Route a physical amplifier input to the zone. input is the 1-based input number wired on the amp.
all_on / all_off	—	Power every output on or off in one shot (amp-side broadcast, no address).
mute_all / unmute_all	—	Mute or unmute every output in one shot.
request_status	address	Ask the amp for one zone's current power / mute / volume.
passthrough	command	Send a raw RTI ASCII command string exactly as typed, for a control the driver does not expose.

Volume scale

GEM presents volume as 0-100. The amp works in a negative dB range on the wire, and the driver converts in both directions, so you always set and read 0-100. Two things to know:

• Because the amp's dB steps are coarser than 100 GEM units, several adjacent slider positions can map to the same actual dB value — a tiny nudge may not change the sound.
• Newer firmware uses roughly a -62..0 dB range, which is what the conversion assumes. Some older AD units use a wider -79..0 range; on those the GEM number will read proportionally lower than the amp's own display. Treat it as relative rather than an absolute dB readout.

Selecting a source (input)

The AD-4x/AD-8x is an input-switching audio matrix: any of its physical inputs can feed any output. To route an input to a zone, send set_input with the zone's address and the physical input number wired on the amp — for example from a macro, a UI button, or an AV-zone source mapping.

info

zone.input vs zone.source

set_input addresses the amp's own physical input number. That is separate from GEM's zone.source, which is an internal reference to a configured AV Source and is owned by the AV-routing logic. When you wire up source selection, drive set_input with the amp input number — do not put a raw amp input number into zone.source.

Troubleshooting

Symptom	Check
Device won't connect.	Confirm the amp's IP and that TCP control is enabled on port 23. Only one control client can hold the port — close any RTI setup tool or third-party controller that may be holding it.
A zone never updates or ignores commands.	Confirm the zone Address is the plain 1-based output number (1-4 or 1-8), entered without leading zeros. GEM pads it for you; a pre-padded or out-of-range address will not match a real output.
Volume slider feels backwards or compressed.	The amp works in negative dB and the driver scales it to 0-100. On older firmware using the wider -79..0 range the GEM value reads proportionally low — see Volume scale.
Power or mute state lags behind reality.	The amp reports state in response to a status request. Trigger request_status on the zone (or reconnect the device) to force an immediate refresh.
Selected input never shows in GEM.	Expected on this TCP driver — it sets input but does not read it back. Use the HTTP variant if you need the live input reflected.

TCP vs HTTP

Stay on this rti_ad8 TCP driver by default — it is lighter weight and reports state without a polling loop. Switch to rti_ad8x_http only if the amp's TCP control port becomes unresponsive after weeks of uptime while its web UI keeps working, or if you specifically need the live selected-input readout.

Related

• Devices — add and configure the amplifier.
• Zones — one zone per amplifier output.
• AV Zones — surface each output on the AV control pages.
• RTI AD-4x / AD-8x (HTTP) — the web-interface variant of this same amplifier.