User manual
Publication 1747-UM011F-EN-P - May 2007
Identifying the Components of Your Processor 95
• UL listed to US and Canadian Safety Standards, CE compliant, 
C-Tick marked.
The figure below shows some of the hardware components of the 
SLC 5/05 processors (1747-L551, 1747-L552, and 1747-L553).
SLC 5/05 Hardware Components
The table below provides a general explanation of the processor 
status indicators.
SLC 5/05 Status Indicators
xx:xx:xx
_______ . _______ . _______ . _______
FORCE
ENET
RS232
RUN
FLT
BATT
RUN REM PROG
SLC 5/05 CPU
Memory 
Module
Left Side View
Front View
Channel 0 
RS 232 
(DH-485, 
DF1, or 
ASCII)
Battery 
(provides 
back-up 
power for the 
CMOS RAM)
Serial Number and 
Catalog Number
Channel 1 
Ethernet 
(10Base-T)
Keyswitch
Write-on area 
for IP Address
Ethernet
Hardware 
Address
Operating System Download Protection Jumper 
– do not move unless updating processor 
Operating System firmware.
Processor 
Status 
Indicator
When It Is Indicates that
RUN 
(Color: green)
On (steady) The processor is in the Run mode.
Flashing (during 
operation)
The processor is transferring a program from 
RAM to the memory module.
Off The processor is in a mode other than Run.
FLT
(Color: red)
Flashing (at power up) The processor has not been configured.
Flashing (during 
operation)
The processor detects a major error either in the 
processor, chassis, or memory.
On (steady) A fatal error is present (no communication).
Off There are no errors.










