Datum bc632D, Руководство пользователя

Страница: 61 / 82

Datum Inc bc632D Wall Mount LED Display (Rev A) A-1
APPENDIX A
DIGITAL TIME TRANSMISSION PROTOCOL
A.0 INTRODUCTION
This document defines the Digital Time Transmission Protocol as used by Datum timing products. The
protocol allows devices to be synchronized to a common source of time. In addition, it allows several
devices (typically displays) to synchronize to multiple time references using a common cable.
A.1 PHYSICAL
A.1.1 DEVICE CONNECTORS
Each device will have at least one RJ11 connector for receiving timing signals. Optionally, the device
can have a second RJ11 for transmitting or daisy-chaining the signal.
The pin assignments for the devices are as follows:
Receiver Transmitter:
1 n.c. 1 n.c.
2 GND 2 GND
3 TX(+) 3 RX(-)
4 TX(-) 4 RX(+)
5 GND 5 GND
6 n.c. 6 n.c.
A.2 SIGNAL DESCRIPTION
TX(+), TX(-)
5-Volt balanced signal, complying with EIA RS-485. These lines carry the timing signals. Several
transmitters may share the same line.
RX(+), RX(-)
5-Volt balanced receiver, complying with EIA RS-485. These lines carry the timing signals. Several
transmitters may share the same line.
GND
Signal ground.
n.c.
Not Connected. These pins are not used. Do not connect to these pins unless you have a specific
use for them.