Dialight D1RW-L13-008 Vigilant L866/L885 LED Based Dual Red / White Catenary - Manual (Page 17)

Document No.
9100-127-1426-99 Rev D
Release Date: 10/26/2010
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Dialight Corporation 1501 Route 34 South Farmingdale NJ 07727
Tel: 732.919.3119 Fax: 732.751.5778 Web: www.dialight.com
Page 17 of 25
Section 18: Appendix A: Serial Port Specification
Overview
The serial port on the microcontroller is accessible through the J7 connector
located on the microcontroller board. It can be used to configure the strobe unit,
monitor it for status information, or provide override capability for the external
control signals. The port itself, as well as the protocol for accessing it, is
described below.
Connection
This port sends and receives raw serial data; it should be noted that there is no
level shift performed on the signals from the microcontroller. If the port is to be
used to connect to a computer or other device with a full RS232 port, a level
shifter will be required. Also, it is good practice to electrically isolate the
microcontroller connection from the computer to protect both the strobe unit and
computer from dangerous voltages.
The serial port connection is through connector J7 on the microcontroller board,
with pin 1 marked by a white arrow. The pinout of this port is listed below.
Pin 1: Ground
Pin 2: +5V (this pin may be used to power an external level shifter, up to 100mA)
Pin 3: RX pin (receive to the microcontroller)
Pin 4: TX pin (transmit from the microcontroller)
Pin 5: No connect
The port has the following characteristics:
19200 baud
8 data bits
One stop bit
No parity bit
No flow control
While a connection to the port can be made through HyperTerminal or a similar
simple serial communication package, it should be noted that the data received
from the port is encoded in binary rather than ASCII, and therefore will be
unreadable by such software.
Protocol
There are three sets of data that can be transmitted across the serial connection:
Configuration, Status and Override. All “Master” transactions are TO the
microcontroller board, and all “Slave” transactions are FROM the microcontroller
board.