3 Terms and definitions

Only words EIS uses in a sense a reader could not guess are defined here. A module, an enclosure, a bus board, a power supply, a cable, a rail, a rail insert, and a mounting screw mean what they mean in any Eurorack catalog; clauses 5 to 7 say what EIS requires of each.

product type

What a requirement applies to: module, enclosure, bus board, power supply, power converter, or cable.

feature

An optional set of requirements a product claims in addition to its product type, named FAMILY-KIND-DIRECTION: PWR-BUS-IN, PWR-DC12-IN, PWR-A6-IN, or PWR-A15-IN for a power domain it takes at an entry and the matching -OUT for one it gives at outlets; VID-REF-IN, VID-REF-OUT, VID-REF-PASSTHRU, or VID-REF-LOOPTHRU for a video reference port; CTRL-USB-DEV for a service port and CTRL-USB-HOST for a case host. In a power designator the word names the topology and the number the rail voltage: BUS is the Eurorack bus, DCnn a single-rail nn V DC domain, Ann a bipolar ±nn V analog domain (6.1). A feature describes what happens behind the panel or inside the case; a port on the front is in the port list.

port and port list

A port is one jack or connector on a module. The port list is the part of a module's documentation that names, for every port, its signal class or unclassified, the range it claims when that is not the class default, and, for a port that generates or locks to a video reference, the formats it supports (SIG-001, VID-001). It is published in the manual or a claim file.

signal class and range

A signal class is a named set of level and impedance limits for a port, such as MOD-AUDIO or MOD-VIDEO (7.2). A range is the full-scale swing a port is built for, such as B10 (−10 to +10 V) or U1 (0 to +1 V); a class lists the ranges it takes and its default.

patch jack

A 3.5 mm mono socket on a module's front panel that takes a patch cable between modules and carries a class from 7.2 or is unclassified. A 3.5 mm TRS socket for MIDI, headphones, or a stereo pair is a port, not a patch jack; EIS recommends that it survive a mono patch plug all the same (7.1).

class ceiling and damage limit

The nominal level of a class is the level an output puts on the port, such as ±5 V for audio; the full scale is the swing the port's range allows, ±10 V at B10; thresholds are what a gate, trigger, or clock input reads; line level, in 7.4, is the level of a coaxial signal's own standard at a terminated input, a different quantity from the line levels of external audio in Annex I. The class ceiling is the largest signal that is still in class; an output claiming the class does not exceed it. The damage limit is the level an input withstands indefinitely without damage. On every patch input it is ±12 V (SIG-002), whatever the class ceiling: a MOD-VIDEO input has a +1.2 V class ceiling and a ±12 V damage limit.

cover, mounting face, throat, seat, and D

On a rail, cover is the amount of panel face the rail hides; the mounting face is the face the panel bears on; the throat is the opening in front of the insert that the screw passes through; the seat is the depth of the insert's front face behind the mounting face; D is the depth behind the mounting face at which metal closes the cavity a screw tip enters. Cover limits the board clearance (5.2.2); seat and D set the screw length window (5.3).

video sync

The horizontal and vertical timing pulses of a video signal, alone (black burst, bi-level or tri-level video sync) or within a composite picture. EIS writes video sync in full, so the word is never ambiguous, and uses it for the pulses and their structure (7.3); the signal a row distributes to lock its modules is the video reference.

video reference

The signal a row's video modules lock their timing to: black burst, or bi-level or tri-level video sync, of one 7.3 format; a composite picture carries video sync but is not the reference. It travels behind the panel on the 75 Ω coaxial interface (7.4), from a VID-REF-OUT to each VID-REF-IN, and never on a patch jack (7.1). A product's reference ports are claimed by kind: VID-REF-IN, VID-REF-OUT, VID-REF-PASSTHRU (a buffered pass-through), VID-REF-LOOPTHRU (a loop-through with a termination switch). A video reference distributor is any product, usually a bus board, with VID-REF-PASSTHRU ports beside its VID-REF-IN: the tree is the star of 75 Ω cables from its PASSTHRU ports to each module's VID-REF-IN.

power domain, power entry, and outlet

A power domain is a set of rails with its own connectors, distribution, and limits: the bus (+12 V, −12 V, optional +5 V), PWR-DC12 (12 V DC), or PWR-A6 (±6 V) (6.1). A power entry is where a domain enters a product: a module's power header, a DC entry, or a PWR-A6 entry. An outlet is where a power supply, a power converter, or a distribution product delivers it: a supply's output terminals, a bus board's headers, a product's PWR-DC12 outlets, a converter's PWR-A6 outlet. A power converter is a source for one product, mounted on or beside it, that makes one domain from another.

0 V and protective earth

0 V is the reference every rail and signal of a row is measured from: the 0 V pins of the power header, the sleeve of a patch jack, the shell of a coaxial jack, and the −V of a DC rail. Protective earth is the mains safety conductor. They are different conductors; a system joins them at one point, the bond a supply publishes (6.3).

DC entry and DC rail

A DC entry is the inlet at which nominal 12 V DC from an external adapter enters a product: a center-positive barrel (DC-BAR21 or DC-BAR25) or a multi-pin connector (DC-VH2 from a DC distribution product, or, above 10 A, DC-DIN4, DC-MF6, or DC-MF8). The DC rail is the 12 V DC that a DC entry feeds, one +V and −V pair, carried to modules directly or through a DC distribution product on DC-BAR21 or DC-VH2; each module filters or regulates it locally. The DC rail is not the ±12 V bus (6.7).

CTRL-USB port and case host

A CTRL-USB port is a USB 2.0 device port behind a product's panel through which its settings are listed and changed with the MIDI 2.0 standards (8.1). A CTRL-USB device is a product with such a port. A case host is a module that claims CTRL-USB in the other role: it connects to the CTRL-USB ports of a case and edits them.

video timing format

A named raster, such as 525i59.94 or 1080p30, with its line count, sample clock, and video sync structure tabulated in data/video_timings.json. 7.3 lists the formats EIS defines.

provenance

The origin of a requirement's value, recorded per row in data/requirements.json: quoted from a dated external publication; inherited from a Doepfer A-100 convention or the Intellijel 1U format, with the page and the date it was retrieved; measured on a named vendor part; calculated from other EIS requirements, which the record names; or eis, set by EIS itself.

Requirement language

EIS does not use RFC 2119 MUST, SHOULD, or MAY, and has no "should" level.

Every shall statement in a normative clause carries a requirement identifier, written in prose without the EIS- prefix (PANEL-009), and the requirements register lists it. A may statement is a permission and need not carry one. A recommendation carries none. Text in a normative clause that uses none of these words is informative: it explains, gives an example, or restates a requirement made elsewhere. Sections, tables, and annexes marked informative impose no requirements. Where a clause and the register differ, the register governs the level and the product types, and the clause governs the technical content.