Siemens SIMATIC S7-1200 System Manual

S7-1200 Programmable controller
System Manual, V4.2, 09/2016, A5E02486680-AK
1309
Online and diagnostic tools
15
15.1
Status LEDs
The CPU and the I/O modules use LEDs to provide information about either the operational
status of the module or the I/O.
Status LEDs on a CPU
The CPU provides the following status indicators:
● STOP/RUN
– Solid yellow indicates STOP mode
– Solid green indicates RUN mode
– Flashing (alternating green and yellow) indicates that the CPU is in STARTUP mode
● ERROR
– Flashing red indicates an error, such as an internal error in the CPU, an error with the
memory card, or a configuration error (mismatched modules)
– Defective state:
- Solid red indicates defective hardware
- All LEDs flash if the defect is detected in the firmware
● MAINT (Maintenance) flashes whenever you insert a memory card. The CPU then
changes to STOP mode. After the CPU has changed to STOP mode, perform one of the
following functions to initiate the evaluation of the memory card:
– Change the CPU to RUN mode
– Perform a memory reset (MRES)
– Power-cycle the CPU
You can also use the LED instruction (Page 450) to determine the status of the LEDs.

Siemens SIMATIC S7-1200 Specifications

General

CPU Type	CPU 1211C, CPU 1212C, CPU 1214C, CPU 1215C, CPU 1217C
Communication	PROFINET
Analog Inputs	2
Analog Outputs	2
Power Supply	24V DC
Expansion Modules	Signal Modules (SM), Communication Modules (CM)
Programming Languages	LAD, FBD, SCL
Dimensions	90 mm x 100 mm x 75 mm
Program Memory	50 KB to 150 KB (depending on model)