Using the Modbus Ports
122 870 USE 101 10 V.2
Modbus Port 2, ContinuedDefault
Parameters The factory-set default communication parameters for Modbus Port 2 are:
l9600 baud
lEVEN parity
l8-bit RTU mode
l1 stop bit
lModbus network address 1
lRS232 protocol
Auto-Logout
Feature Only
with RS232
If the Serial Option Adapter is used and the RS232 port is chosen, auto-logout is
supported. If a programming panel is logged into the CPU vi a the s erial port and its
cable gets disconnected, the Processor Adapter automatically logs out the port.
This auto-logout feature is designed to prevent a lock-up situation that could
prevent other host stations from logging in on other ports.
Auto-logout is not available for any RS485 port, including the RS485 option on the
Serial Option Adapter. The user must log out of the processor using the
programming software.
Note: Processor Adapters support only one stop bit. If you change this default
setting in the configuration software, the Processor Adapter will ignore the
change.
Note: The default protocol must be changed from RS232 to RS485 for the
171 CCS780 00,171 CCC 780 10 Processor Adapters or the port will not
function. The 171 CCC 980 20 and 171 CCC 980 30 change
automatically.