Rockwell Automation 1785-Lxxx Enhanced and Ethernet PLC-5 Programmable Controllers User Manual
Page 158

Publication 1785-UM012D-EN-P - July 2005
10-8 Communicating with Devices on a Serial Link
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
Duplicate detect
Whether you want the controller to
detect and ignore duplicate messages
Select the desired setting.
ACK timeout
The amount of time you want the
controller to wait for an
acknowledgment to its message
transmission
Enter a value 0-65535. Limits are defined in 20 ms intervals. For example
to wait 40 ms, type 2. The recommended time elapse is 1 second.
Specify 1 second by typing 50.
MSG appl
timeout
The number of seconds within which
the reply message must be received
before the error bit is set on the
message. The timer starts when the
ladder program first initiates the
message and is restarted if/when the
ACK is received
Enter one of the following values:
1:30-60 seconds
2:60-90 seconds
3:90-120 seconds
4:120-150 seconds
5:150-180 seconds
6:180-210 seconds
7:210-240 seconds
NAK receive
The number of NAKs your controller
can receive in response to a
transmitted message
Enter a value 0-255. The recommended setting is 3.
DF1 ENQS
The number of enquiries (ENQs) that
you want the controller to send after
an ACK timeout
Enter a value 0-255. The recommended setting is 3.
This Field
Specifies
Configure by Doing the Following