Stewart Filmscreen BRIC

Driver for a Stewart Filmscreen BRIC motorized projection screen — the controller that drives a Stewart screen's masking panels (and, on masking-plus-drop models, the screen drop) to a set of stored geometries. In a dedicated cinema this is what snaps the picture area between 16:9 flat-panel viewing, 1.85 "flat" cinema, and 2.35 "scope" as you change content, so the black masking always frames the image with no visible border.

The BRIC controller speaks a simple RS-232 ASCII protocol, so in almost every install GEM reaches it through a serial-to-IP adapter — a Global Caché iTach, a Brainboxes, or any raw-TCP serial gateway — and GEM connects to that adapter's IP and port. You add the screen once as a device; there are no zones to create.

This driver recalls presets — it does not "open" and "close" like a shade

Even though a screen lives in the Shades family, this driver exposes only preset recalls (home plus ten aspect / user presets). There is no Open / Close / Stop here — the geometry each preset moves to is programmed at the BRIC controller, and GEM simply tells the controller "go to preset N."

Prerequisites

• Program the screen's geometries at the BRIC controller first. Using Stewart's BRIC setup procedure, store the masking (and drop, if applicable) positions you want for each aspect ratio into the controller's preset slots. GEM recalls slots the controller already owns — it does not set masking limits or teach positions.
• Put the BRIC controller behind a serial-to-IP adapter and note the adapter's IP address and raw-TCP port (for a Global Caché iTach the serial port is commonly 4999). Configure that serial port to match the BRIC's serial settings — this driver expects 19200 baud, 8 data bits, no parity, 1 stop bit, no flow control. If the baud or framing don't match, the BRIC ignores every frame and nothing moves.
• Leave the BRIC at controller address 01. This driver always addresses controller unit 01 (the factory default). A multi-controller install, or a BRIC re-addressed to another unit, needs a custom command set to reach it.
• Network: give the adapter a static IP or DHCP reservation and make sure its TCP port is reachable from the GEM host.

Setup — add the screen

1. Go to System → Devices → Add Device and set:
   • Driver → Stewart Filmscreen BRIC. GEM pre-fills the Shades subsystem (the driver's first hint) and a screen device type. You can instead place the screen under AV if you organize screens alongside your projector and sources — either is fine, it does not change how the presets work.
   • Gateway IP → the LAN IP of the serial-to-IP adapter fronting the BRIC controller (not the BRIC itself — the controller has no IP of its own).
   • TCP Port → the adapter's raw serial-passthrough port (e.g. 4999 on a Global Caché iTach). Both fields are required — this driver has no default port.
2. Enable the device. GEM opens a persistent TCP connection to the adapter and holds it open, reconnecting automatically with a backoff if the link drops. There is no login — the BRIC protocol is unauthenticated.
3. There is nothing to "discover" and no zones to create — each BRIC screen is a single endpoint. You drive it directly with the preset commands below.

tip

You can enter the address as ip:port

If you leave Gateway IP and TCP Port blank but set the device Address to 192.168.1.50:4999, GEM splits it into the IP and port for you on first connect. Filling the two fields explicitly is clearer, but either works.

How control works

Every preset is sent to the BRIC as a short ASCII string terminated by a carriage return, in the form 01 + M + a single digit. The leading 01 is the BRIC controller address (fixed at 01); the digit is the preset slot the controller recalls:

You call	Sent to the BRIC	Recalls
home	01M0	The controller's home / reference position (slot 0)
preset_16x9	01M1	Preset slot 1 — factory-named for 16:9 viewing
preset_235	01M4	Preset slot 4 — factory-named for 2.35 scope
preset_7	01M7	User preset slot 7

GEM does not compute masking positions — it only asks the controller for a stored slot. What each slot actually does (how far the masking panels travel, whether the screen also drops) is whatever you programmed into that slot at the BRIC controller. The four aspect-named presets are just friendly labels for controller slots 1–4; slots 5–9 are yours to define.

Driving the screen

Because a BRIC screen has no zones, you trigger its presets one of three ways:

• From the device's Commands tab (the command tester) — pick a preset and run it to confirm the wiring and slot programming during commissioning.
• From a UI button — bind a control/button to the device command (e.g. preset_235) so a homeowner can pick an aspect ratio from a touchpanel.
• From macros — the usual home-cinema pattern. A "Watch a movie (Scope)" scene might power the projector on, dim the room, and recall preset_235 on the screen in one press; a "TV" scene recalls preset_16x9. Pairing the screen preset with the projector and lighting in one macro is how most integrators expose it.

Device attributes

Attribute	Set by	Purpose
ip (Gateway IP)	You	LAN IP of the serial-to-IP adapter connected to the BRIC controller. Use a static IP or DHCP reservation.
port (TCP Port)	You	Raw-TCP serial-passthrough port on the adapter (e.g. 4999 on a Global Caché iTach). Required — there is no default.

The driver inherits the generic TCP advanced fields (reconnect timing, command throttle, keep-alive ping) but a BRIC screen needs none of them — leave them at their defaults.

Command reference

Run these from the device's Commands tab, from a UI button, or from macros. The driver declares exactly these ten commands, each a fixed preset recall — none take arguments:

Command	Sent	Recalls
home	01M0	Home / reference position
preset_16x9	01M1	Preset 1 — 16:9 (1.78:1)
preset_4x3	01M2	Preset 2 — 4:3 (1.33:1)
preset_185	01M3	Preset 3 — 1.85:1 "flat" cinema
preset_235	01M4	Preset 4 — 2.35:1 "scope" cinema
preset_5	01M5	User preset 5
preset_6	01M6	User preset 6
preset_7	01M7	User preset 7
preset_8	01M8	User preset 8
preset_9	01M9	User preset 9

There is no "go to X %" or continuous-position command — the BRIC works entirely in stored presets. If you need an aspect ratio the four named presets don't cover, put its geometry into one of the user slots (5–9) at the controller and recall that slot.

What GEM knows — and what it doesn't

The BRIC integration is open-loop. GEM transmits preset recalls but the BRIC controller sends nothing back that GEM tracks, so GEM has no read-back of the screen's real masking position. The device reflects only the last preset GEM sent — it will not update if someone recalls a preset from the BRIC's own keypad or a third-party controller. For predictable state, drive the screen from GEM (or from GEM-triggered scenes) rather than mixing in manual operation.

Troubleshooting

Symptom	Check
No response on any preset, device shows connected	Confirm the adapter's serial settings match the BRIC — 19200 baud, 8-N-1, no flow control (a common mistake is leaving the adapter at 9600). The BRIC ignores frames at the wrong baud silently. "Connected" only proves the TCP link to the adapter is up, not that the serial side is talking to the BRIC.
preset_5–preset_9 do nothing	These are user-programmable slots. Out of the box they may be undefined and will silently no-op — program the geometry into the slot at the BRIC controller first.
Masking moves to the wrong geometry	The slot's stored position is wrong, not GEM. Re-teach that preset at the BRIC controller; GEM only recalls the slot number.
Never connects	Verify the Gateway IP and TCP Port point at the serial-to-IP adapter, that the port is reachable from the GEM host, and that no other software is already holding that serial port open.
Whole screen is unreachable but the adapter pings	The BRIC may have been re-addressed off unit 01, or you have more than one controller on the bus. This driver only talks to unit 01.

Related documentation

• Devices — add the BRIC screen and set its Gateway IP / TCP Port.
• Subsystems — the Shades subsystem the screen lands in (or place it under AV).
• Commands — where the preset recalls appear and can be tested.
• Macros — build "Movie (Scope)" / "TV (16:9)" scenes that recall a screen preset alongside the projector and lighting.
• AV Zones — pair the screen and projector into a cinema AV zone.