Going Online And Connecting To A Cpu - Siemens SIMATIC S7 System Manual

Online and diagnostic tools

9.2 Going online and connecting to a CPU

The CPU also provides two LEDs that indicate the status of the PROFINET communications.
Open the bottom terminal block cover to view the PROFINET LEDs.
● Link (green) turns on to indicate a successful connection
● Rx/Tx (yellow) turns on to indicate transmission activity
The CPU and each digital signal module (SM) provide an I/O Channel LED for each of the
digital inputs and outputs. The I/O Channel (green) turns on or off to indicate the state of the
individual input or output.
In addition, each digital SM provides a DIAG LED that indicates the status of the module:
● Green indicates that the module is operational
● Red indicates that the module is defective or non-operational
Each analog SM provides an I/O Channel LED for each of the analog inputs and outputs.
● Green indicates that the channel has been configured and is active
● Red indicates an error condition of the individual analog input or output
In addition, each analog SM provides a DIAG LED that indicates the status of the module:
● Green indicates that the module is operational
● Red indicates that the module is defective or non-operational
The SM detects the presence or absence of power to the module (field-side power, if
required).
Description
Field-side power is off
Not configured or updated in progress
Module configured with no errors
Error condition
I/O error (with diagnostics enabled)
I/O error (with diagnostics disabled)
9.2 Going online and connecting to a CPU
An online connection between the programming device and a target system is required for
loading programs and project engineering data to the target system as well as for activities
such as the following:
 Testing user programs
 Displaying and changing the operating mode of the CPU
 Displaying and setting the date and time of day of the
 Displaying the module information
 Comparing online and offline blocks
 Diagnosing hardware
270
CPU
DIAG
(Red / Green)
Flashing red
Flashing green
On (green)
Flashing red
-
-
S7-1200 Programmable controller
System Manual, 11/2009, A5E02486680-02
I/O Channel
(Red / Green)
Flashing red
Off
On (green)
-
Flashing red
On (green)