8/22/2009 7:35 PM | |
Joined: 8/22/2009 Last visit: 6/8/2023 Posts: 26 Rating: (0) |
But when PLC is in STOP mode there are no comm faul, so the slave don't will stop |
Regards. |
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8/24/2009 2:56 AM | |
Joined: 10/7/2005 Last visit: 11/11/2024 Posts: 3026 Rating: (1057) |
Dear MemoGG let's clear up some possible sources of confusion first: If an S7 PLC goes into STOP, it's DP Master interface enters the so called "CLEAR" state, Profibus communication is however STILL active! A DP Master in "CLEAR" state still does the following: 1.) Parameterisation and Configuration of DP Slaves For example, if you power up your S7 in STOP mode, allDP Slaves will be parameterised and configured and your Profibus will be in a healthy state. 2.) Cyclic Slave data exchange 2a.) IF the DP Slave has the entry"Failsafe = 0" in its GSD file, then this meansit will still receive its outputs from the DP Master and all outputs will be send as a "0" value (i.e. all Slave outputs will be switched OFF). 2b.) IF the DP Slave has however the entry"Failsafe = 1" in its GSD file, then this meansit will NOT receive any output information from the DP Master at all anymore (i.e. the lenght of output data is zero). The DP Slave behaviour now dependsentirely on its configuration (this mode allows tofor example retain the last output ORto go to pre-defined failsafe state as a reaction to aPLC stop. 3.) Send the so called "Global Control command" with the "Clear" bit on Thistells/informs each DP Slave that the DP Master is in the"Clear" state. Attached is a nice little document which describes the above inmore detail (refpage 8 &9). I hope this helps and please let us know more about you setup and configuration (e.g. type/model of of Drives,HWconfig setupof them and internal Drives configuration with regards to the DP Slave interface). AttachmentPofibus_Introduction (Acromag).pdf (514 Downloads) |
Cheers |
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8/26/2009 10:45 AM | |
Joined: 10/7/2005 Last visit: 11/11/2024 Posts: 3026 Rating: (1057) |
Thanks for the update MemoGG this is definetely a case that our "good friends" from Schneider will have to answer (perhaps worthwhile telling them that you are considering using Siemens Simocode's instead of the Tesys to keep the pressure up). Anyway, without the failsafe paramter in the GSD file I would assume (I never tested this case) that failsafe=0 applies (i.e. the PLC will send all outputs as "0" when it goes into Stop, if you had a Profibus analyser like Profitrace you could verify this yourself). Assuming this is the case (all outputs zero) you will no longer "tell" the Tesys that it is in "remote" control mode (output 0.5 of the control word). Ifyou'd now configured it do a so called 'bumpless changeover" to local mode, I wonder if this is causing the problem (as it might not get the local Stop command and will keep on running). Anyway, food for thought, please let us know the outcome (and do yourself a favour and use Simocode's next time round). |
Cheers |
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10/28/2009 11:45 AM | |
Posts: 1 Rating: (0) |
Hello MemoGG, the TeSys T does not support the failsafe mode, the Keword failsafe is not in the GSD file. For a network problem, like you disconnect the Profibus cable to the device, in the configuration (accessible via PowerSuite) you have the fallback feature. There you can set the behavior of the device, if the profibus communications fails. If the plc goes in stop mode, there is no communication fault, so the device will not go into the fallback state. To cover this state, you have to add a "custom predefined" program or write a "full custom" program from scratch. The TeSys T is a really powerful Motormanagement tool, much more powerful then other devices I know. In the attachment you find the manual about the Custom logic editor. If you need further help, you can contact me. Attachment1639507_02a55.zip (444 Downloads) |
Last edited by: jungen at: 10/28/2009 1:11 PMLast edited by: jungen at: 10/28/2009 11:50 AM |
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