From Javier Gorrochategui’s proposals to Teguibus and the non-polarized bus, the documents trace a history of innovation around two-wire systems, but they do not describe a single technology or, on their own, prove worldwide priority.
This documentary article examines communication solutions and their technical evolution. The general history of Tegui covers the company’s history separately.
Short answer: Gorrochategui has documented contributions to two-wire door entry systems dating back to 1988. We can recognize this track record without claiming he invented the world’s first two-wire door entry system or treating an application date as a product launch date.
Contents
- Why reducing the number of wires was decisive
- The 1988 proposal
- The 1994 digital development
- Both patents at a glance
- Low power consumption and coded calls
- Teguibus and the non-polarized bus
- The importance for renovation
- Documentary timeline
- What we can say about its contribution
- Sources and documents consulted
Why reducing the number of wires was a decisive idea
In a conventional door entry system, different functions are arranged using shared conductors and call lines, with variations depending on the system. In existing buildings, more wiring and connections can mean more work when the time comes to upgrade.
But reducing the number of wires is not just a matter of removing conductors. Each dwelling must be identified, only the called terminal activated, and the system powered without the accumulated load preventing it from working.
“Two-wire” can refer to the number of conductors in a section, a digital bus with addressing, or the audio part of an installation that uses another medium for video. The term alone does not identify a protocol or establish compatibility.
1988: A two-wire communication proposal
On October 10, 1988, Spanish application 8803079 was filed and published as ES2011143 A6, “Communication system between a point and secondary units, such as an automatic door entry system”. The bibliographic record identifies Gorrochategui as the inventor and gives the publication date as December 16, 1989.
It is worth distinguishing the numbers: 8803079 is the application number; ES2011143 A6 identifies the publication. They are not two different patents.
The summary describes handsets connected in parallel over two conductors. One is ground, and the other carries the call, audio communication, and door-release activation signals. This is direct evidence of work on a two-wire architecture several years before the 1994 development.
The record establishes that proposal and its dates. By itself, it does not show when it began mass production, under what product reference it was sold, or whether other manufacturers had developed earlier solutions.
1994–1998: the digital system is described in detail
On October 24, 1994, application 9402204 was filed, titled “Two-wire communication system for door-entry systems.” The cover page of the official document ES2103187 A1 identifies Javier Gorrochategui Grajirena as the applicant and inventor, and gives August 16, 1997 as its publication date.
The bibliographic record for ES2103187 B1 gives April 1, 1998 as the publication date of the grant. A1 and B1 belong to the same application; they are not two independent inventions.
| Information | Document |
|---|---|
| Application | 9402204, filed on October 24, 1994. |
| A1 publication | ES2103187 A1, August 16, 1997. |
| B1 publication | ES2103187 B1, April 1, 1998, according to the bibliographic record. |
| Applicant and inventor in A1 | Javier Gorrochategui Grajirena. |
The 1994 specification expressly cites application 8803079 as prior art. It explains that the earlier solution used FM modulation and demodulation, and points to cost and power-consumption difficulties per telephone. This documents a technical relationship between the two works, without needing to infer one from their dates.
Both patents at a glance
| Aspect | 1988 proposal: ES2011143 A6 | 1994 proposal: ES2103187 A1 |
|---|---|---|
| Central idea | Connect the panel to parallel-connected telephones using two wires. | Organize low-power communication per terminal and selection using digital pulses. |
| Call and communication | The abstract places the call, audio, and door-opener activation on the signal wire, with another wire for ground. | The specification details reset, coding, and acoustic call as distinct stages. |
| Relationship between the documents | Application 8803079: prior art cited by the later work. | Cites the prior art and addresses cost and power-consumption limitations. |
| Source used | Bibliographic record and abstract of the publication. | Official application PDF, plus the B1 document for its publication date. |
| Scope of the comparison | It does not establish a first sale date or a commercial reference. | It does not demonstrate identity with all later commercial buses; the video example adds coaxial cable. |
This comparison summarizes the documents consulted. It is not a table of equivalents between devices or a wiring diagram.
The advance: coordinating terminals with little wiring and low power consumption
The summary of ES2103187 A1 combines telephones connected by two wires, low-power CMOS integrated circuits, and a digital pulse sequence. In the described section, selecting the home does not depend on an individual call line: it is handled electronically.
The problem of cumulative power consumption
Each connected telephone loads the line. The specification explains that the high impedance of the CMOS circuit, together with the input resistance, reduces individual power consumption. On page 2, it cites around 50 to 60 microamps per telephone and proposes keeping consumption low with 255 telephones.
These values correspond to the implementation described. They are not specifications for any current device or instructions for measuring an installation. The specification also distinguishes idle, off-hook, and door-opening states through changes in power consumption; microamps and milliamps must not be confused.
Three phases for calling the correct home
| Phase | Function |
|---|---|
| 1. Reset | Prepare the circuits to interpret the new sequence. |
| 2. Encoding | Select the telephone based on the pulses and its code. |
| 3. Acoustic call | Make the selected terminal ring using distinct pulses. |
The telephones use binary-programmed microswitches. The example describes up to 255 codes using eight microswitches. Counters and timing prevent other terminals from activating while passing through intermediate states.
Lower consumption per terminal + coded selection + state coordination.
The point is not just to use two wires, but to coordinate how the system operates collectively over that line.
Two telephones in one home and state control
The specification covers two telephones with the same code. Both can receive the call, but the one picked up first must maintain the connection and block the other. The document links this decision to detecting states through power consumption: two active terminals could create a condition that might be mistaken for the door being opened.
It is a solution for the implementation described, not authorization to add telephones to any existing installation.
Multiple entrances and concierge service
The application describes main and secondary panels, as well as a concierge station. It covers residents’ calls, visitor filtering, and a log of requests when the corresponding line is busy. Some communications from the panel to the concierge station use FM-modulated pulses; not all links should be described as if they handled the signal in the same way.
Its example includes a keypad, call codes, an alphanumeric directory, and an RS-232 interface for programming. These are features of the document, not capabilities attributed to all older digital equipment.
An essential clarification: the video example adds coaxial cable
On page 5 of ES2103187 A1, the communication pair is retained in the description of the video door-entry system, but the corresponding coaxial cable is added for the video telephones.
In that example: two wires plus coaxial cable.
It is not accurate to describe it as universal transmission of audio, video, and power over just two conductors.
From invention documents to Teguibus and the non-polarized bus
The official “2-wire digital door-entry system” manual defines a two-wire bus shared by the telephones. Its introduction allows for up to 50 entrance panels and 255 homes per panel, as well as a concierge station. These are the capacities of the documented system and should be read subject to its conditions, not as universal limits for all Tegui products.
The official TEGUIBUS page, meanwhile, explains that it eliminates call-return wires from homes and connects entrance panels via a two-wire network. For video, it specifies twisted pair or coaxial cable.
A match in functions or conductors is not enough to prove that a commercial system exactly reproduces a patent. Nor does it justify conflating Teguibus with any later system called “2 WIRES” or “two non-polarized wires.”
The 2013 industry reference
Porteralia published “Tegui Digital Bus gives way to 2 wires” on March 22, 2013. It dates the development of Tegui Digital Bus to the late 1990s and states that the new two-wire, non-polarized audio system had been on the market for about four years at the time.
This reference suggests a date of around 2009. It should be treated as a retrospective timeline based on an industry source, not as an official launch date certified by a contemporary catalogue. Nor does it prove that the later offering was identical to the invention presented in 1994.
| Document or designation | What it contributes | What it does not prove on its own |
|---|---|---|
| Gorrochategui patents | Architectures and technical solutions documented with dates. | The date a specific product first went on sale. |
| Teguibus, official documentation | System architecture and means of transmitting the video signal. | Compatibility with any other two-wire bus. |
| Non-polarized bus, industry reference from 2013 | Retrospective evidence of commercial development. | The exact official launch date or identity with the earlier patents. |
The real significance: opening up renovation options for buildings
The value of two-wire technology does not depend on claiming absolute precedence. Sharing a line, identifying dwellings electronically, and reducing cabling requirements can make certain renovations easier, provided the wiring and system conditions allow it.
The official Teguibus page highlights the elimination of call-return wires. A 2013 industry article links the non-polarized offering to renovation without changing the wiring. This is an advantage described for that context, not a guarantee that any existing wiring can be reused.
From audio to video: an option documented in 2021
On page 7, the Tegui 2021 catalogue reviewed explains that 2-WIRE technology lets users install an audio system that is ready to add video later. This option to upgrade in stages is useful for communities wishing to spread the cost of renovation over time.
That statement does not imply that any old installation can be converted to video by replacing only the phone. Components, power supply, topology, distances, wiring, and configuration must be checked against the documentation for the specific generation.
Maintenance requires identifying the exact system
Phones, entrance panels, power supplies, and configuration matter just as much as the equipment’s appearance. Two products described as “two-wire” are not necessarily compatible. The wiring diagrams and manuals for each series are essential before replacing components.
This article contains no connection instructions and does not recommend test power supplies. Electrical identification and any work must be carried out by qualified personnel.
Documentary timeline
| Date | Document or milestone | What it establishes |
|---|---|---|
| October 10, 1988 | Application 8803079, published as ES2011143 A6. | Proposal for communication between the panel and secondary units over two wires. |
| December 16, 1989 | ES2011143 A6 publication, according to the bibliographic record. | Publication date of the document for that proposal. |
| October 24, 1994 | Application 9402204, later ES2103187. | System with low power consumption and coded digital signaling. |
| August 16, 1997 | ES2103187 A1 publication. | Publication of the application consulted in the official PDF. |
| April 1, 1998 | ES2103187 B1 publication, according to the bibliographic record. | Publication corresponding to the grant. |
| Late 1990s | Development of Teguibus according to Porteralia’s 2013 retrospective. | Industry indication, pending corroboration with commercial sources from the period. |
| Around 2009 | Non-polarized audio: an estimate based on “four years” in the 2013 article. | Approximate dating, not a dated official launch. |
| 2021 | Tegui catalog consulted, page 7. | Offering that explains audio preparation for adding video later. |
Was it pioneering?
The answer depends on what that word means. There is direct evidence of Gorrochategui’s proposals dating from 1988 and of a detailed digital solution submitted in 1994. This makes it possible to highlight a documented record of innovation. It does not establish an international ranking of the earliest manufacturers.
| Claim | Evidence | Assessment |
|---|---|---|
| Worked on door-entry communication over two wires in 1988. | ES2011143 A6 fact sheet and summary. | Supported by the document. |
| Developed a specific low-power digital proposal. | ES2103187 A1 specification. | Supported by the document. |
| Tegui marketed that exact patent on a specific date. | Dated commercial evidence establishing that correspondence is lacking. | Not demonstrated in this study. |
| Tegui invented the world’s first two-wire door-entry system. | No exhaustive international comparison has been conducted; the documentation records prior work. | Should not be claimed. |
We can speak of a documented precursor in the limited sense established by this sequence: an inventor with two-wire work dating from 1988, predating the later commercial offering described here. We do not use “precursor” as a synonym for first in Spain or the world.
Conclusion: invention, product, and launch are distinct events
The two-wire system deserves its own article because of the problem it solves: coordinating many terminals with limited wiring and suitable electronics. The documented sequence combines a proposal from 1988, a digital solution developed in 1994, and later documentation of commercial systems.
A patent explains an invention; a manual describes an installation; a catalog presents an offering. Keeping these distinct makes it possible to recognize Gorrochategui’s contribution and Tegui’s evolution without turning an indication into a slogan of primacy.
Sources and documents consulted
- ES2011143 A6: Communication system between one point and several secondary units, such as an automatic door entry system. Bibliographic record and summary; application 8803079, dated October 10, 1988.
- OEPM, ES2103187 A1: Two-wire communication system for automatic door entry systems. 13-page PDF. Page 1: details and summary; 2: background; 3–4: operation; 4–5: concierge unit and entrance panels; 5: video application with coaxial cable; 6: claims.
- ES2103187 B1. Bibliographic record for checking the publication date of April 1, 1998, not as a substitute for reading the A1 PDF.
- Tegui, Technical Manual: 2-Wire Digital Door Entry System. Retrieved introduction: common bus, system capacities, and organization.
- Tegui, TEGUIBUS system. Retrieved official description of call returns, network, and video transmission.
- Porteralia, Tegui Digital Bus gives way to 2 wires, March 22, 2013. Retrospective industry source for the late nineties and the lead-up to 2009.
- Tegui, 2021 price list catalog, file Catalogo_Tarifa_Videoporteros_Porteros_Tegui_2021.pdf held by the store. Page 7 consulted directly: audio prepared for later video. No specific monthly edition that has not been verified is attributed to this file.
- Original image, “2-Wire System. Door Entry and Video Door Entry,” provided by Tegui Distel. Date and edition unverified; not used to date patents or launches.
The two-entrance diagram dated 1996 mentioned during preparation is not included as a verified milestone: that document has not been located for review. A diagram from that date, by itself, would not prove the commercialization of a specific patent either.
Historical and technical study, not an assessment of legal validity or installation instructions. No claim is made that these patents are identical to ES2107942 B1 or that the historical systems are compatible with current products.