2 Add the attribute S7mc to the system attributes of the block right click

2 add the attribute s7mc to the system attributes of

This preview shows page 42 - 45 out of 618 pages.

2. Add the attribute "S7_m_c" to the system attributes of the block ( right-click > Properties > System attributes ) and set the value to true . 3. Open the block by double-clicking in the block folder. 4. Click the element names that you wish to transfer and open the Properties (right-click). 5. Add the attribute "S7_m_c" and set the value to true . 6. Close the block. 7. Select the block again by clicking in the block folder. 8. Open the Special Properties ( Edit > Special Properties > Operation and Monitoring ). 9. Select the Operation and Monitoring box. 10. Close Special Properties .
Image of page 42
Creating a Project Process Control System PCS 7, Tips and Tricks A5E00080064-01 3-3 3.1.3 Determining defective station in the case of I/O access failure Entry ID: 1032718 - Date: 09/20/1999 QUESTION: How can I determine from which rack an I/O access failure comes in order to prevent the OB122 (I/O access failure) from being called unnecessarily? ANSWER: If you access the I/O directly in your program, without using the PCS 7 driver blocks, you get the problem when the I/O fails that the OB122 (I/O access failure) is called for each access. This overloads the CPU. If the I/O fails, you should determine the station affected and inhibit I/O access . The OB86 contains the start information required for this. You can read out this information using the SFC6 (RD_SINFO). The function block attached below evaluates the SFC6 (RD_SINFO) accordingly. You must incorporate the block in OB86 and in OB100 . You must not call the block in a cyclic OB. If you call the attached FB (FUNCTION.pdf) in the OB100, in the source code you must manually set the desired variable presettings for the rack failures when starting up the CPU. It is best to set all the variables so that the entire I/O can be accessed . In the case of an I/O failure, this variable is reset. If the OB86 (rack failure) is called, it is determined whether a rack has failed or returned. The outputs QRACKF (failure) and QRACKOK (rack return) are set accordingly to 1. The output SUBN_ID specifies the number of the subnetwork, the output RACK_NO the PROFIBUS address of the failed station. The values are available always only for one call of the function block. For more information on evaluating refer to the on-line Help of the SFC6 (RD_SINFO) and the OB86. In the proposed evaluation you must define a variable for each station monitored . This variable is then set to 1 when the station fails. It is set to 0 again when the station returns. Depending on this variable, access to the I/O must be inhibited, to prevent the OB122 from being called. You also have the option of defining a Boolean output in the block, which is set according to the status. You must copy the SFC6 (RD_SINFO) into the block container before compiling the SCL codes. FUNCTION.pdf (4 KB)
Image of page 43
Creating a Project Process Control System PCS 7, Tips and Tricks 3-4 A5E00080064-01 3.1.4 Configuring CPUs and CPs not listed in the HW Config Entry ID: 1529424 - Date: 06/05/2000 QUESTION: Which CPU / CP do I have to configure in the HW Config if the CPU / CP is not yet listed in the HW Config?
Image of page 44
Image of page 45

You've reached the end of your free preview.

Want to read all 618 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture