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Entry type: FAQ Entry ID: 32151540, Entry date: 12/22/2008

What should you watch out for when using an ASM456 in a Y-link (IM153)?

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If you are using the ASM456 in a Y-link (IM153), this might affect operation of the PROFIBUS.

Fig. 01

A too short a timeout setting (PollTimeOut) in the CPU can adversely affect the acyclic services of the PROFIBUS.
You can avoid this behavior by changing the C1_Response_Timeout in the GSD file of the ASM456.

You can correct the case described by changing the timeout settings via the GSG file (6GT2 002-0ED00) of the ASM456. Reduce the "C1_Response_Timeout" from the default value of 10 (= 100ms) to 5 (= 50ms).
The table below describes the procedure required for this.

No. Procedure Notes / Explanation
1 If ASM456 is already configured, then remove the module from your HW Config project and run Save and compile.

Fig. 02
2 The GSG file is in the following directory on your hard disk: <Drive:>\ Program Files\Siemens\Step7\S7DATA\GSD. Alternatively, you can download the GSG file (station type: ASM456) in Entry ID: 113562 and unpack it with WinZip.
3 Open the GSG file with a simple editor, e.g. Notepad. Reduce the parameter "C1_Response_Timeout" from the default value of 10 (= 100ms).

Repeat this with the GSE, GSF, GSI and GSS file(s).
Make sure that this time is not too short, otherwise the ASM456 causes timeout errors.

If you have changed the language of the SIMATIC Manager, access is made to a GSD in a different language. Therefore, you should change all the files.
4 Save and integrate the changed GSG file in the STEP 7 hardware catalog . The following FAQ describes how to proceed in this case: "How do you integrate a GSD file into the STEP 7 HW Config for PROFIBUS or PROFINET?" (Entry ID: 2383630).
5 Drag the ASM456 GSG from the hardware catalog PROFIBUS DP -> Other Field Devices -> Ident Systems -> MOBY -> ASM456 and drop it in your HW Config project. Then run Save and compile and Load in module to integrate the changed GSG.