About DOLLx8


About the Digital One Line Link x8 network protocol

The first DOLL (Digital One Line Link) version was developed as a joint project between Norway, England, Hungary, and their teams. It started in the early 1990s and are used in home automation, electronic control- and audio system. The early DOLL system was back then based on 18-bit Pulse-Width Modulation (PWM) where the communication was 120 Khz and was divided into 10-bit address and 8-bit data word. The signal was sent three times before the interface of the receiver side (with the right set address code) was able to approve the data transfer and accept the 8 data bits. The reason why the data was sent 3 times was that it should make sure that the receiver did not receive erroneously information in the data network.

Some years later, around 1995, until 1999, the DOLL was further developed together with a new group of developers in New Zealand and then became the DOLLx8 versions 1.0 to 3.0. DOLLx8 was then also extended into applications such as audio where it was emphasized on that the system should send feedbacks to the master unit and where one could check the status of all devices connected to the network. The DOLLx8 system was in the period 2001 to 2003 re-developed so that it could receive commands via text messages rather than just data and address bits, and was then developed for both cascade (2-port) and parallel networking using RS-232 and USB. Such cascade and parallel networks had its pros and cons, where links between the units had weaknesses in such way that it had limited cable length of 16 meters, while the RS-232 TTL version had the same limitation but with only 5 meters. With such limitations, the best solution was a cascade network where each device in the network was acting as a signal buffer, where data was received on port one and went out buffered on port two. The major drawback of such solution was that if a device did not work as intended due to errors in the system, the rest of the devices would not be able to communicate with either master devices nor the rest of the network. In the same period MISOLIMA received export subsidies from the Department of International Trade Promotion and held exhibition at Comdex 2002 in Las Vegas, United States.

From 2003 to 2006 DOLLx8 was also developed for embedded systems within aviation through Aeronautical Software and Technology Lab (ASLT) in Thailand where ASLT developed a DOLLx8 streaming system for the transfer of GPS-, navigation (navaid), terrain, and MEMS gyroscope data for Electronic Map Display (EMD) and Primary Flight Display (PFD). The system could then receive GPS data in NMEA and binary formats, along with other aircraft data and transmit this along with the flight plan, terrain and navigation data so that both instruments could use the same flight data over one or two DOLLx8 data lines. The advantage of such technology was that the aircrafts or helicopters would need only one GPS antenna for two or more GPS based instruments.

The streaming system that was developed back then by ASLT was also used in later versions and is now a permanent part of DOLLx8 in connection with sensor streaming technologies and GSM data transfer via GPRS.