Rockwell Automation 57C329 Remote I/O Communications, AutoMax - Manual (Page 68)

4Ć6
diagnostics, and then communicate the new rail configuration to the
Remote I/O master.
WARNING
REMOVING OR INSERTING A MODULE OR I/O INTERCONNECT CABLE WITH
POWER APPLIED MAY RESULT IN UNEXPECTED MACHINE MOTION OR
LOSS OF PROCESS CONTROL. STOP THE MACHINE OR PROCESS IN AN
ORDERLY FASHION AND DISCONNECT THE POWER TO THE SYSTEM
BEFORE YOU REMOVE OR INSERT A MODULE OR I/O INTERCONNECT
CABLE. FAILURE TO OBSERVE THESE PRECAUTIONS COULD RESULT IN
BODILY INJURY.
4.6.3 Rail I/O Configuration (M/N 57C330)
The Remote I/O network transmits rail data from the master drop to
the slave drop or from the slave drop to the master drop depending
on whether the rail contains output or input modules, respectively.
Therefore, input andoutput modules cannot be mixedwithin a rail.
Each rail can contain up to eight input or output modules.
The rail configuration is determined approximately every 20 milliseconds
while the Remote I/O network is active. The Remote I/O Headcan
determine if there is a rail connected at any port but cannot directly
determine whether the rail contains input or output modules. The system
determines whether a particular rail contains input modules or output
modules based on the data going to or from the rail.
When a rail is first determined to exist at a particular port, that rail is
marked as undefined." If an undefined" rail passes back data that
has nonĆzero values, it is then defined as an input register whose
data will be transmitted to, but not from, the master drop. Conversely,
if nonĆzero data is written to an undefined" rail, it is then defined as
an output register to which data will be transmitted from, but not to,
the master drop. Once a particular register is defined as input or
output, it will remain defined as such regardless of future data values
until one of the following occurs:
WARNING
REMOVING OR INSERTING A MODULE OR I/O INTERCONNECT CABLE WITH
POWER APPLIED MAY RESULT IN UNEXPECTED MACHINE MOTION OR LOSS
OF PROCESS CONTROL. STOP THE MACHINE OR PROCESS IN AN ORDERLY
FASHION AND DISCONNECT THE POWER TO THE SYSTEM BEFORE YOU
REMOVE OR INSERT A MODULE OR I/O INTERCONNECT CABLE. FAILURE TO
OBSERVE THESE PRECAUTIONS COULD RESULT IN BODILY INJURY.
a.) power is cycledto the remote drop;
b.) the line goes from an ACTIVE state to INACTIVE;
c.) the rail is removed (disconnected) from the Remote I/O system.
When a slave drop is initially polled by the Remote I/O master, it will
transmit the rail configuration to the master. The master will use this
information to control access to that drop's registers in the master's
dual port memory via the Multibus. It will allow Read/Write access for
registers defined as OUTPUT or not yet defined, and Read Only