User guide

Using the Modbus Ports
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870 USE 101 00 V.2.2
Modbus Port 2,
Continued
Default
Parameters
The factory-set default communication parameters for Modbus Port 2 are:
9600 baud
EVEN parity
8-bit RTU mode
1 stop bit
Modbus network address 1
RS232 protocol
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 protocol must be changed from RS232 to RS485 for the
171 CCS 780 00and 171 CCC 780 10 Processor Adapters or the port will not
function.
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 via the serial 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.
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