Rockwell Automation 1775-S5_SR5,D17756.5.5 User Manual PLC-3 FAMILY I/0 - Manual (Page 31)

Configuring the Scanner through LIST
Chapter 2
2-5
You can only perform an auto configuration when:
the controller is in program load mode
power is applied to the I/O chassis
the processor restart lockout switch is set to allow the I/O chassis to be
restarted from the processor
If power is not applied to the I/O chassis, the processor attempts to perform
an auto configure, and since the I/O chassis does not respond, the scanner
does not enter it in the I/O chassis list. For an entry to get into the I/O
chassis list in auto configure, a valid path must exist between the scanner
and the I/O adapter module for the I/O chassis.
ATTENTION: You can replace a 1775-S4A, -SR scanner with
a 1775-S5, -SR5 scanner, however, you must:
perform a logical save of memory without saving the module
status area (E2)
clear memory after replacing one scanner with another.
restore the previously stored memory
configure each 1775-S5, -SR5 scanner communication
channel in LIST.
Failure to observe this caution could result in equipment
damage and/or undesired machine operation.
Reconfiguration
The reconfiguration selection sets configuration parameters for the scanner.
The reconfigure selection implements changes that you have made in LIST
for the communication channel. For example, suppose you list an I/O
chassis 3 times in the I/O chassis scanning sequence list, and you change
the list to include that chassis 6 times. The scanner does not change its
polling sequence until you select reconfigure for the I/O channel.
Important: When selecting reconfigure, the scanner executes a
reconfiguration of the selected channel only. Also, when you power-up the
PLC-3 controller, a reconfiguration automatically executes.
If an asterisk is next to the reconfiguration selection, changes have been
requested but not implemented. Upon selecting reconfigure, the scanner
implements the changes and removes the asterisk.