PLC concepts
4.5 Status LEDs
S7-200 SMART
System Manual, V2.3, 07/2017, A5E03822230-AF
101
4.5
Status LEDs
The CPU and EM use LEDs to provide information about operational status.
CPU status LEDs
The CPU provides the following LED status indicators:
State
LED Behavior
Description
STOP
STOP: on
RUN, ERROR: off
Applicable when the CPU is in
STOP Mode
STOP with Force
RUN: off
STOP: blink at 1 Hz rate
ERROR: off
Applicable when the CPU is in
STOP mode and a value is
forced
RUN
RUN: on
STOP, ERROR: off
Applicable when the CPU is in
RUN Mode
RUN with Force
RUN: on
STOP: blink at 1 Hz rate
ERROR: off
Applicable when the CPU is in
RUN mode and a value is
forced
Busy
STOP, RUN: blink out of phase
at 2 Hz rate
ERROR: off
Applicable when after card
evaluation during power-up or
restart, a memory card opera-
tion is in progress or when a
restart operation is in progress
Memory Card Inserted
STOP: blinks at 2 Hz rate
RUN, ERROR: off
Applicable when someone in-
serts a memory card into a
powered-on CPU
Memory Card OK
STOP: blinks at 2 Hz rate
RUN, ERROR: off
Applicable when after card
evaluation during power-up or
restart, a memory card opera-
tion completes successfully
Memory Card Error
STOP, ERROR: blink in phase
at 2 Hz rate
RUN: off
Applicable when after card
evaluation during power-up or
restart, a memory card opera-
tion terminates with an error
Defective
STOP, ERROR: on
RUN: off
Applicable when the CPU is in
Defective Mode
Ping
STOP, RUN: blink out of phase
at 2 Hz rate
ERROR: blink in phase with
RUN
Applicable when the CPU re-
ceives a Signal DCP control
request (Flash LEDs)
EM status LEDs
The expansion modules (EM) provide the following LED status indicators: