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Library Modbus TCP PN RED 5 Digit or 6 digit adressing?

Created by: mark1507 at: 2/3/2020 7:09 PM (3 Replies)

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2/3/2020 7:09 PM	Rate (0)
mark1507 Platinum Member Joined: 6/23/2008 Last visit: 11/7/2024 Posts: 1168 Rating: (283)	Hello everybody, I am currently trying out the library mentioned in the title (6AV6676-6MB10-0AX0) and have also read the documentation. From a customer I received an address table for the controller (Mitsubishi) that we are supposed to connect to, in which it looks as if the server is working with 6 digit addressing (e.g. 300001 = value x, 300002 = value y, etc.) The wizard does only allow a 5 digit mapping (you can put only 4 digits in the mask and I guess one digit for the type will be added to the request telegram). Now I wonder if the library mentioned can handle it. The examples in the documentation in chapter '8.3 Example for address mapping' make it look as if the library only works with 5 digit addressing. Does it matter if I don't need to access registers greater than 9999? I need to know this before telling our customer he has to purchase the license. Thanks in advance and best regards...
	Last edited by: mark1507 at: 02/04/2020 07:22:01 "Expert" does not necessarily mean Siemens employee. Please cross-check your requirements always with official Siemens documentation. Also "Experts" are pleased about feedback. Please don't send support requests as PM. Questioners who don't follow up their thread will be put to my list of users to be ignored.
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2/4/2020 8:57 AM	Rate (1)
Wüstenräuber Gold Expert Joined: 10/3/2008 Last visit: 8/28/2024 Posts: 961 Rating: (124)	Hi, the addresses from your customer are not the absolute addresses, which are sent via the bus. These addresses are only the addresses in the application layer. It is often used by Allen Bradley users. If a device uses 5-digit addresses in the application layer, then the input registers can be addressed from 30001 to 39999. Via the bus only the absolute addresses are sent: 0 (30001) to 9998 (39999). If a device uses 6-digit addresses in the application layer, then the input registers can be addressed from 300001 to 365535. Via the bus only the absolute addresses are sent: 0 (300001) to 65534 (365535). If a device don't use an application layer but the absolute addresses, the complete address area can be used: 0 to 65535. The modbus library don't use an application layer. The blocks use the absolute addresses 0 to 65535. If your customer uses 300001 = value x, 300002 = value y, then you must subtract 300001 from the values and use these new values in the wizard/modbus block. Wüstenräuber

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2/4/2020 6:46 PM	Rate (0)
mark1507 Platinum Member Joined: 6/23/2008 Last visit: 11/7/2024 Posts: 1168 Rating: (283)	Hello Wüstenräuber Thanks for your support, highly appreciated ! Just to make sure I got you right I'll sumarize... If I want to read server's 1st input register I'll put value '4' at input 'DATA_TYPE' and '0' to input 'START_ADDRESS' of block 'MB_PNHCL'. The server will deliver the data of register 300001. So I use the input 'START_ADDRESS like an offset, from 300001. If the server has registers from 30001 to 39999 it simply makes no sense to use an offset greater than 9998. I guess in that case server would deliver an error. For reading input registers (3x..) from 1 to 9999 there is no difference if the server can handle input registers from 30001 to 39999 or 300001 to 365535 If I should read the input registers from 301025 to 301124 I will put 1024 to 1123 at the wizard (for input registers) and use values between 1024 and 1123 at 'START_ADDRESS'. Above is true if we are talking about a server with application layer, means the 1st register is named 300001 at server side. Would be great if you could confirm or correct above statements. Best regards...
	"Expert" does not necessarily mean Siemens employee. Please cross-check your requirements always with official Siemens documentation. Also "Experts" are pleased about feedback. Please don't send support requests as PM. Questioners who don't follow up their thread will be put to my list of users to be ignored.
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2/5/2020 8:39 AM	Rate (2)
Wüstenräuber Gold Expert Joined: 10/3/2008 Last visit: 8/28/2024 Posts: 961 Rating: (124)	Hi, 1. yes 2. yes 3. yes 4. yes 5. yes 6. yes Wüstenräuber

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