FAQs - frequently asked questions

SUMMARY

A collection of FAQs - Frequently Asked Questions

CONTENTS

  1. QUESTION: Changing parameters in the SoftPlc7.ini-File do no show any effect?
  2. QUESTION: When starting the program the error message 'No blocks were found. An empty project with an empty OB1 is generated.' Turns up?
  3. QUESTION: How can I find out, which Offline-Folder belongs to which Step7-Program?
  4. QUESTION: The PG-Device can not connect to SoftPLC7. What settings have to be checked?
  5. QUESTION: All parameters defined in the SoftPLC.ini-File are ok, but the S7-Program enters STOP-Condition after a short time. What is the reason?
  6. QUESTION: What actions must be taken to make a SoftPLC7 OPC-Server work properly?
  7. QUESTION: Why are the Operand-Areas L, DB and DI always empty when using the Debug-Panel?
  8. QUESTION: What is the quickest way to find out the line in a STEP7 program that initiates the value change of an operant?
  9. QUESTION: When downloading a STEP7-Program the SoftPLC7 outputs the message - not enough memory available on the Memory Card. Will it caus problems?

QUESTION: Changing parameters in the SoftPlc7.ini-File do no show any effect?


Check, that the wanted SoftPLC7.ini-File is really used when calling up the program.
If no (or a wrong one) [ini=<File name>] is defined, the system uses default values for any missing parameter when starting the program.

QUESTION: When starting the program the error message 'No blocks were found. An empty project with an empty OB1 is generated.' Turns up?


The defined SoftPlc7 Project Directory does not contain any *.bin files.
The message may be ignored safely if the S7-Project should be loaded via the PG-Interface, the needed files will be created that time.
(TCP/IP interface should be used, due to loading time)
Advisable is to convert the Offline Folder of the original Step7-Program to a SoftPLC7-Project.

QUESTION: How can I find out, which Offline-Folder belongs to which Step7-Program?


Use the SIMATIC Manager to open any OB in a Step7-Program in AWL-Code. Add an empty line at the end and save the project. Check date/time of all Offline-Folders; that one with the latest date/time-stamp belongs to the modified Step7-Program.

QUESTION: The PG-Device can not connect to SoftPLC7. What settings have to be checked?


Check both ends whether the same interface is defined.

PG:          'PC Adapter (MPI)' or 'TCP/IP- <Name>'
SoftPLC7:    In pull-down menu 'Extras', Item 'PG-Interface' 
                - MPI  or TCP/IP should be ticked.

If no connection via TCP/IP can be established set the address within SoftPLC7 to '0.0.0.0'.

Prerequisite for debugging via TCP/IP is that the Communication Processor in the original project is capable to do TCP/IP protocol. If not add a CP 443-1 and define a valid IP-Address within the SoftPLC7.

QUESTION: All parameters defined in the SoftPLC.ini-File are ok, but the S7-Program enters STOP-Condition after a short time. What is the reason?


If the INTF indicator turns red, a Step7-Error occurred. Maybe it was tried to read from a not (yet) existing block. Check what restart methods is intended for the STEP7-Program. Sometimes the restart blocks (OB100 - OB102) create data blocks. The restart method defines the OB to be executed; it can be defined in the pull-down menu 'Extras' of the start window. If the CPU stops in any case, switch to test mode (Ctrl+T); the last block worked on is shown. Put a breakpoint (F9) in front of the highlighted Assembler code und restart the program. The CPU stops prior the instruction that lead to the error. Sometimes the values listed in the window point to what the failure cause. Check that all System Function Blocks are supported by SoftPLC7: In the pull-down menu 'File' of the start window select 'Analysis of calling'; check the entries at the bottom of the left column, any SFB and SFC not in brackets must be shown in bolt font. If not, these blocks will not be substituted by an equivalent high-level-language dll when called up. It is also possible that SFC51 is called up by a not yet supported SZL-ID. That has to be checked individually. Check in 'Analysis of calling' also for hints of a missing block. It is strongly recommended to run the consistence test Ctrl+K).

QUESTION: What actions must be taken to make a SoftPLC7 OPC-Server work properly?


After executing the program, the server is registered That causes the SoftPLC7 to send cyclical the values of the requested OPC-Items to the OPC-Server.

If the OPC-Client still does not receive updated values choose 'canonical' as type of the data format. Due to the MFC only unsigned 8Bit, signed 16Bit, signed 32Bit and real data type are supported. The workaround allows use of other data type also.

QUESTION: Why are the Operand-Areas L, DB and DI always empty when using the Debug-Panel?


For those Operand-Areas always a special context (an Assembler-Instruction) is necessary. When the CPU is in RUN-Modus, the operands in the Debug-Panel are updated in-between the OB1-Cycles that means no local data and no opened DBs are available. Only in STOP-Modus meaningful Values can be displayed. The CPU may be put into STOP-Modus by setting a breakpoint (F9) in the program code.

QUESTION: What is the quickest way to find out the line in a STEP7 program that initiates the value change of an operant?


Assuming the value of byte 10 in DB100 is expected to stay constant, but at the end of an OB the value has changed.
In the pull-down menu 'View' select 'Test mode', there click 'Operand' (last column in the lower part) and input DB100.DBB10 in the opened dialog window.
Start the CPU and look for the value change in the renamed column.
Either the command in question is already obvious, or the value changes when calling the block. If so, set a breakpoint there (F9), when halted delete the breakpoint (F9) and continue with program flow in the called block (F11 and F5 afterwards).
Now proceed as you did in the previous block.

Alternative you set a conditional breakpoint:
In Test mode via pull-down menu select 'Conditional breakpoints...'' you can define the conditions. Accept the conditions with 'Apply' and 'OK'. The CPU enters the halt-condition as soon the defined conditions match.

QUESTION: When downloading a STEP7-Program the SoftPLC7 outputs the message - not enough memory available on the Memory Card. Will it caus problems?

You can safely ignore that message, since internally the SoftPLC7 is organised different.