Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers User Manual
Page 160
Publication 1785-UM012D-EN-P - July 2005
10-10 Communicating with Devices on a Serial Link
User mode char.
The character for the mode attention
character (above)
Enter a character. If the attention character you want to use is a control
character, specify the ASCII equivalent.
When the controller encounters the attention character and the user
mode character, the controller sets channel 0 communication to user
mode. The remote mode change option must be ENABLED.
Serial Settings
Baud rate
Communication rate for channel 0
Configure all devices in the system for
the same communication rate
Select 110, 300, 600, 1200, 2400, 4800, 9600, or 19.2k bps.
Parity
Parity setting for channel 0
Parity provides additional message
packet error detection.
Select NONE or EVEN.
Bits per character
Select the number of bits that make up
a transmitted character.
Select 7 or 8.
Error detect
Whether you want error detection set
to BCC or CRC
Select one of the following:
BCC: the controller sends and accepts messages that end with a BCC byte
for error checking. BCC is quicker and easier to implement in a computer
driver.
CRC: the controller sends and accepts messages with a 2-byte CRC for
error checking. CRC is more complete checking
Configure both stations to use the same type of error checking.
Stop bits
Match the number of stop bits to the
device with which you are
communicating
Select 1, 1.5, or 2.
Control line
Select the mode in which the driver
operates.
Select a method appropriate for your system’s configuration:
If you are not using a modem, choose NO HANDSHAKING.
If you are using a full-duplex modem, choose FULL-DUPLEX.
Option Settings
Station address
The station address for channel 0 on
the DF1 half-duplex link
Enter a valid DF1 address (0-376 octal).
DF1 retries
The number of times the remote
station retries a message before the
station declares the message
undeliverable
Enter a value 0-255. The recommended setting is 3.
This Field
Specifies:
Configure by Doing the Following