| 摘要 |
<p>A signal for use on a wired network interconnecting electronic devices comprises a base voltage for conveying power to the electronic devices; a pulsed voltage signal bearing coded information for transfer between the electronic devices; and a digital signal superimposed onto selected portions of the pulsed voltage signal. The digital signal comprises a carrier signal modulated by a digital encoded data signal for transfer between the electronic devices, and the digital encoded data signal represents an original digital data signal encoded in accordance with a code scheme that ensures that there is at least one transition, between high and low binary values, between every data bit of the data signal. The code scheme may be 4B/5B, 8B/10B, Manchester or bi-phase mark encoding. This is used in fire alarm networks, for example, to convey multimedia or other data such as control signals, whilst maintaining compatibility with existing protocols using the pulsed voltage signal.</p> |
