6/15/2011 7:02 AM | |
Posts: 28 Rating:
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we have a CPU224XP as slave that has Modbus communication and recieved some hardwire Digital inputs and want send them via Modbus to master.how can I do this? |
6/15/2011 7:23 AM | |
Joined: 10/7/2005 Last visit: 8/27/2024 Posts: 3018 Rating:
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Hello zmzm a simple search at https://support.automation.siemens.comrevealsthe following FAQ's and I hope it helps: How do you implement MODBUS communication with S7-200? Where in STEP 7 Micro/WIN can I find the operations libraries for the Modbus RTU protocol and USS protocol? Definition of variables of the USS and MODBUS library P.S: There's a fair few Forum dicussions available on this subject too which can be found with the same search. |
Cheers |
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6/15/2011 7:52 AM | |
Joined: 3/21/2006 Last visit: 7/26/2024 Posts: 10228 Rating:
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Hello, How do you implement MODBUS communication with S7-200? Best regards, Hristo MIhalev |
6/15/2011 9:05 AM | |
Joined: 4/24/2006 Last visit: 8/27/2024 Posts: 8724 Rating:
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Dear zmzm, Here is link to manual: S7-200 System manual See chapter 12 for more information about Modbus communication. If you are a Modbus slave, you only have to use the mentioned blocks. The master will ask the Hardwired inputs by using the right Modbus Addressing Best regards, Wizard |
6/15/2011 11:27 AM | |
Joined: 3/18/2008 Last visit: 12/8/2023 Posts: 1750 Rating:
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Dear Zmzm, Little addition.. you also need modbus library for modbus communication. Have a look at following FAQ. Where in STEP 7 Micro/WIN can I find the operations libraries for the Modbus RTU protocol and USS protocol? |
Last edited by: Amit_86 at: 6/15/2011 11:28 AMVANDE MATARAM..... |
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7/18/2011 7:51 AM | |
Posts: 9 Rating:
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Dear Wizard, Is it that simple? just to use the block in the Modbus library; MBUS_INIT and MBUS_SLAVE and the rest is up to the master? ><" how about when receiving write instruction from master? is it the same? if so, the slave will only contain the block MBUS_INIT and MBUS_SLAVE and nothing else? correct me if im wrong, so the modbus address mapping is already fix 00001-00128 are discrete outputs mapped to Q0.0-Q15.7 10001-10128 are discrete inputs mapped to I0.0-I15.7 30001-30032 are analog input registers mapped to AIW0-AIW62 40001-4xxxx are holding register mapped to V memory So the only thing we can change is the holding register V memory base on the HoldStart in MBUS_INIT?
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2/24/2015 3:08 PM | |
Joined: 9/3/2014 Last visit: 3/13/2019 Posts: 4767 Rating:
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10/2/2015 1:20 PM | |
Joined: 9/3/2014 Last visit: 3/13/2019 Posts: 4767 Rating:
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New question published by U_636e5741-31e4-422f-a108-945962a9e016 is split to a separate thread with the subject 226-cn CPU fetch data directly from SCADA. Best regards |
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