2/24/2010 4:28 AM | |
Joined: 2/1/2010 Last visit: 11/22/2023 Posts: 25 Rating:
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Hello, Who can give me some suggestionsor documents about SSA? What should master do? What should slave setting? Thank you! |
2/24/2010 6:28 AM | |
Joined: 3/21/2006 Last visit: 7/26/2024 Posts: 10228 Rating:
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Hello, Read at 02/15/2006 4002_vOctober2002-English.pdf Examples: What master/slave communication options are available on PROFIBUS DP? Best regards, Hristo Mihalev |
2/27/2010 2:10 PM | |
Joined: 10/7/2005 Last visit: 8/22/2024 Posts: 3017 Rating:
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Hello linherald you need a Slave (DP or PA) and a Class 2 Master (you do NOT need a Class 1 Master (e.g. PLC) for this to work)
In principal yes. A Class 2 Master is a "device" (typically in form of aPC and a piece of Software) that has a certain set of features/functionality to accomodate Slave diagnostics, configuration, setup etc. Setting of a Slave address via software for DP or PA Slave is also a feature of Calss 2 Master. Most DP Slave on the market do however NOT allow setting of the Slave address via a Class 2 Master (Sabine's advise is rigth on the money here), but instead use DIP switches to set the Address. Some DP and a fair few PA Slaves doaccomodate Class 2 Master related Address setting as well as DIP switches related Address setting(in a mutual exclusive fashion of course). There are even a few rare DP Slaves as well as plenty of PA Slaves out there whose address can only be set via the SSA feature of a Class 2 Master. Commonly used PC based Class 2 Master applications are for example Siemens PDM and E&H Fieldcare. You'll typically find these in Plants were plenty fo PA Devices are used as they act as a central point of access for all PA devices (e.g. to read out diganostics, backup the device configuration, calibrate PA instruments, set up new PA devices etc.). Having said that, Siemens has quite cleverly embeddedthe Set Slave Address functionality (Class 2 Master functionality) into Step 7. You can find it in HWconfig under the PLC menu-->Profibus-->Assign Profibus Address and youuse this togive aSlave a new address (IF your Slave supports this).
I'm just as lost as Sabine here. Once an Address is set for the (via Class 2 Master or DIP switches) Slave is is (should) be there forever. Could you please clarify what exactly you mean by"out of control" (I have seen PA Slaves "loosing" their Class 2 Master assigned address, but this was due to a fault with the firmware of the PA Slave and is a rather rare occurence)? I hope this helps |
Cheers |
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3/1/2010 4:04 AM | |
Joined: 10/7/2005 Last visit: 8/22/2024 Posts: 3017 Rating:
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No it can NOT dear linherald. An S7 PLC can only be a Class 1 Master.
YES you do, as said before Step 7 itself allows you doset/change Slave Addresses (and it does so in aClass 2 Master role). Attached is a pic which will hopefully help and better explain what I mean. |
Cheers |
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3/30/2010 7:37 AM | |
Joined: 2/1/2010 Last visit: 11/22/2023 Posts: 25 Rating:
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Thanks for all your support! I have implemented SSA succefully. Now my question is "How and where can I apply it"? If I have several slaves which are completely the same with the same initial address, then how can I distinguish them with different setting addresses? Do you have some application examples about SSA? Please send it to me if possible, thank you. My E-mail: yonglin.guo@siemens.com |
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