Troubleshooting
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.1
SITRAIN Training for
Automation and Industrial Solutions
Troubleshooting
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.2
SITRAIN Training for
Automation and Industrial Solutions
Objectives
Upon completion of the chapter the participant will ...
...
be able to classify occurring errors as "Errors detected by the system"
and "Functional errors"
...
be familiar with the "Displaying CPU Messages" function
...
be able to read out the diagnostic buffer, interpret it and use it
for troubleshooting
...
be able to read out the I STACK, B STACK and L STACK and
interpret them
...
be able to read out the hardware diagnosis
...
be able to apply the "Monitor/Modify Variables" test function
...
be able to interpret the displays of the "Monitor" test function in the
LAD/STL/FBD Editor and use them for troubleshooting
...
be able to read out the reference data, interpret them and use them
for troubleshooting
...
understand the "Force" function
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.3
SITRAIN Training for
Automation and Industrial Solutions
Categories of Errors
Errors Detected by the System
Recording, evaluating and indicating
errors within a PLC
(as a rule: CPU STOP)
Module failure
Short-circuit in signal cables
Scan time overrun
Programming error (accessing a
non-existent block)
Functional Errors
Desired function is either not executed at all
or is not correctly executed
Process fault (sensor/actuator, cable defective)
Logical programming error (not detected
during creation and startup)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.4
SITRAIN Training for
Automation and Industrial Solutions
STEP7 - Debugging Tools, Overview
Error
Error detected by the System:
General Rule: CPU in STOP
(such as accessing a non-existent DB)
(Diagnostic interrupt of a signal module)
Functional fault:
General Rule: CPU in RUN
(process fault, such as a wire break)
(logical programming error, like a double assignment)
Debugging Tools:
Enable Peripheral Outputs (modify outputs)
Monitor / Modify Variable
Monitor Blocks (Block Status)
Reference Data
- Cross References
- Assignment of I/Q/M/T/C
- Program Structure
- Addresses without Symbols
- Unused Symbols
Regardless of the cause of the error you could use:
Force
Enable Peripheral Outputs
Set Breakpoints
Debugging Tools:
Module Information
- Diagnostic buffer
- I STACK
- B STACK
- L STACK
Hardware Diagnostics
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.5
SITRAIN Training for
Automation and Industrial Solutions
System Diagnostics - Overview
CPU
CPU diagnostics detects
a system error
Diagnostic
interrupt
CPU diagnostics detects
errors in the user program
Error
OB
Diagnostic
buffer
I/O module
Diagnosticscapable module
detects an error
and generates
a diagnostic
interrupt
System
status list
CPU
messages
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.6
SITRAIN Training for
Automation and Industrial Solutions
Displaying CPU Messages
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.7
SITRAIN Training for
Automation and Industrial Solutions
Calling the "Module Information" Tool
SIMATIC Manager
LAD/STL/FBD Editor
Module Information
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.8
SITRAIN Training for
Automation and Industrial Solutions
Module Information Tab: "Diagnostic Buffer"
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.9
SITRAIN Training for
Automation and Industrial Solutions
Interpreting Error Messages in the Diagnostic Buffer
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.10
SITRAIN Training for
Automation and Industrial Solutions
Opening a Block Containing an Error
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.11
SITRAIN Training for
Automation and Industrial Solutions
Diagnostics with I Stack, B Stack, L Stack
Program structure
Block containing error
Point of interruption
Point of interruption
The B stack shows a list of the
blocks that were executed up
to the point of interruption.
You can see the contents of the
accumulators, registers, status word
etc. at the time of interruption in the
I stack.
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.12
You can see the values of the
temporary variables at the
time of interruption in the L stack.
SITRAIN Training for
Automation and Industrial Solutions
Contents of the B Stack
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.13
SITRAIN Training for
Automation and Industrial Solutions
Contents of the I Stack
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.14
SITRAIN Training for
Automation and Industrial Solutions
Contents of the L Stack
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.15
SITRAIN Training for
Automation and Industrial Solutions
Displaying the Hardware Diagnostics
twice
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.16
SITRAIN Training for
Automation and Industrial Solutions
Ex 1: Copying a Faulty Program and Preparing for Troubleshooting
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.17
SITRAIN Training for
Automation and Industrial Solutions
Exercise 2: STOP Troubleshooting
Please Note: That after every STOP error correction, you
must carry out a CPU warm restart. If, after the
warm restart, the CPU once again goes into the
STOP state, there still exists a further STOP
error.
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.18
SITRAIN Training for
Automation and Industrial Solutions
Calling the "Monitor/Modify Variables" Tool
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.19
SITRAIN Training for
Automation and Industrial Solutions
Establishing Trigger Points for "Monitor/Modify Variable"
PII
Trigger point
"Beginning of Scan Cycle"
Monitor / Modify
depending on
Trigger setting
Set
Trigger
Cyclic
program
execution
Update Status / Modify
Values (one time
monitor / modify)
Trigger point
"Transition to STOP"
Trigger point
"End of Scan Cycle"
PIQ
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.20
SITRAIN Training for
Automation and Industrial Solutions
Opening a Variable Table and Establishing a Connection to the CPU
Accessible CPUs
Directly
connected
CPU
Station 1
Configured
CPU
(VAT from
HW Station
"Station 2")
Station 2
Station 3
PG
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.21
SITRAIN Training for
Automation and Industrial Solutions
Testing (Debugging) Blocks using "Monitor" (Block Status)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.22
SITRAIN Training for
Automation and Industrial Solutions
Information Displayed with "Block Debug > Monitor"
LAD/STL/FBD Editor -> Options ->Customize
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
... or
in running status:
right mouse click
on
2/23/2012
PRO1_14E.23
SITRAIN Training for
Automation and Industrial Solutions
Displaying Reference Data
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.24
SITRAIN Training for
Automation and Industrial Solutions
Displaying the Program Structure
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.25
SITRAIN Training for
Automation and Industrial Solutions
Displaying Cross References
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.26
SITRAIN Training for
Automation and Industrial Solutions
Filtering Cross References
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.27
SITRAIN Training for
Automation and Industrial Solutions
Block Correction using Cross References
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.28
SITRAIN Training for
Automation and Industrial Solutions
Go To Location
1 x right
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.29
SITRAIN Training for
Automation and Industrial Solutions
"Find" In Reference Data
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.30
SITRAIN Training for
Automation and Industrial Solutions
Assignment of I, Q, M, T, C
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.31
SITRAIN Training for
Automation and Industrial Solutions
Unused Symbols / Addresses without Symbols
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.32
SITRAIN Training for
Automation and Industrial Solutions
Comparing Blocks (1)
...see
next page
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.33
SITRAIN Training for
Automation and Industrial Solutions
Comparing Blocks (2)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.34
SITRAIN Training for
Automation and Industrial Solutions
"Force" Variables
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.35
SITRAIN Training for
Automation and Industrial Solutions
Exercise 3: Testing the Motor Jog
!!!
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.36
SITRAIN Training for
Automation and Industrial Solutions
Exercise 4: Testing the Quantity Display
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.37
SITRAIN Training for
Automation and Industrial Solutions
If You Want to Know More
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.38
SITRAIN Training for
Automation and Industrial Solutions
Selecting Process and Test Operation
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.39
SITRAIN Training for
Automation and Industrial Solutions
Trigger Conditions for Block Monitoring (1)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.40
SITRAIN Training for
Automation and Industrial Solutions
Trigger Conditions for Block Monitoring (2)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.41
SITRAIN Training for
Automation and Industrial Solutions
Exercise 5: Testing the Evaluation of Fault 4
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.42
SITRAIN Training for
Automation and Industrial Solutions
Testing the Program Execution using Breakpoints (Part 1)
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.43
SITRAIN Training for
Automation and Industrial Solutions
Testing the Program Execution using Breakpoints (Part 2)
Breakpoint
Next
statement
SIMATIC S7
Siemens AG 2006. All rights reserved.
Date:
File:
2/23/2012
PRO1_14E.44
SITRAIN Training for
Automation and Industrial Solutions
