Using Wizards To Help You Create Your Control Program; Handling Errors In The S7-200 - Siemens Simatic S7-200 System Manual

S7-200 Programmable Controller System Manual

Using Wizards To Help You Create Your Control Program

STEP 7–Micro/WIN provides wizards to make aspects of your programming easier and more automatic. In
Chapter 6, instructions that have an associated wizard are identified by the following Instruction Wizard
icon:
Instruction
Wizard

Handling Errors in the S7-200

The S7-200 classifies errors as either fatal errors or non-fatal errors. You can view the error codes that
were generated by an error by selecting the PLC > Information menu command.
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Figure 5-6 shows the PLC Information dialog box
that displays the error code and the description
of the error.
The Last Fatal field shows the previous fatal error
code generated by the S7-200. This value is
retained over power cycles if the RAM is
retained. This location is cleared either whenever
all memory of the S7-200 is cleared or if the RAM
is not retained after a prolonged power outage.
The Total Fatal field is the count of fatal errors
generated by the S7-200 since the last time the
S7-200 had all memory areas cleared. This value
is retained over power cycles if the RAM is
retained. This location is cleared whenever all
memory of the S7-200 is cleared, or when the
RAM is not retained after a prolonged power
outage.
Appendix C lists the S7-200 error codes, and
Appendix D describes the special memory (SM)
bits, which can be used for monitoring errors.
Non-Fatal Errors
Non-fatal errors are those indicating problems with the construction of the user program, with the
execution of an instruction in the user program, and with expansion I/O modules. You can use
STEP 7–Micro/WIN to view the error codes that were generated by the non-fatal error. There are three
basic categories of non-fatal errors.
Program-compile errors
The S7-200 compiles the program as it downloads. If the S7-200 detects that the program violates a
compilation rule, the download is aborted and an error code is generated. (A program that was already
downloaded to the S7-200 would still exist in the EEPROM and would not be lost.) After you correct your
program, you can download it again. Refer to Appendix C for a list of compile rule violations.
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Figure 5-6 PLC Information Dialog Box