Red Lion LEGEND - Manual (Page 36)

PROGRAM COMMUNICATION PORT
When communicating to a Legend Plus via the serial port, the data formats of
both units must be identical. The Baud Rate and Parity Bit/number of data bits are
selected for the data format in this module along with the Unit Address and Serial
Transmit Delay. Serial communication is covered in detail in the SERIAL
COMMUNICATIONS SECTION. The following flowchart shows only the
Communication portion:
BAUD RATE
The Baud Rates available are: 1200, 2400, 4800, and 9600 Baud.
PARITY/ NUMBER OF DATA BITS
The Parity can be ODD-7B (7data bits), EVEN-7B (7 data bits), or No parity-8B
(8 data bits). If any of the extended ASCII characters are to be transmitted serially
(used in mnemonics, custom display line, or in message #0 when MSG0-YES is
configured), the unit must be configured for 8 data bits (NONE - 8B).
UNIT ADDRESS
The Unit Address can range from 00 to 99. This allows addressing of multiple
units on a single pair of wires and a common (RS-485 only), with each unit
capable of having a different address. If only one unit is on the line an address of
zero can be used, eliminating the need for an address command.
SERIAL TRANSMIT DELAY
The Serial Transmit Delay is the minimum amount of time the Legend Plus
unit waits to transmit data to a peripheral unit. The time begins after the Legend
Plus receives a command to transmit data or when a print request is received. The
delay can be set for 0.002 or 0.100 second. This delay time gives the software
controlling an RS-485 interface card time to change the RS-485 port from
transmit to receive mode.
-34-