SIMATIC S7-200/300/400, Step7, PCS7, CFC, SFC, PDM, PLCSIM,
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Apollo11
- Posts: 4
- Joined: Thu May 06, 2010 6:46 pm
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by Apollo11 » Tue Feb 08, 2011 10:50 am
Hi!
I have a problem how to convert a 38-bit binary value to a dec-value.
The PLC is a Siemens 400-cpu and have a 32-bit accumulator, so the solution must use 2 DoubleInteger variables to show the dec value.
Do anyone have a solution or tip how to solve this problem.
Who will be the first to solve my problem?
//Apollo11
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Homeroid_BL
- Posts: 259
- Joined: Fri Apr 03, 2009 3:24 pm
- Location: Bosnia and Herzegovina
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by Homeroid_BL » Tue Feb 08, 2011 7:04 pm
More precisely, please.
38-bit or 32-bit or 64-bit binary?
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Apollo11
- Posts: 4
- Joined: Thu May 06, 2010 6:46 pm
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by Apollo11 » Wed Feb 09, 2011 8:53 am
A RFID-reader sends a serialnumber in 38-bit Binary-code this value should be converted to datatype=dec in the PLC-system.
In some way I need to find a solution who can work with bigger value than 32-bit.
Because the Siemens-system has only a 32-bit accumulator to work with.
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dehell
- Posts: 104
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- Location: Europe
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by dehell » Wed Feb 09, 2011 5:02 pm
Hi,
Could you explain how and where the data are send to the Siemens PLC?
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Apollo11
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- Joined: Thu May 06, 2010 6:46 pm
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by Apollo11 » Thu Feb 10, 2011 10:53 am
OK!
The RFID-reader sends the data over a Profibus-connection.
The data are 12-byte long in binary-code. In this data-area you can read out following data.
Binarycode from left to right.
Codetype = bit 1-8 bit (8-bit long) convert to 0-255 dec, no problem.
FilterType = bit 9-11 (3-bit long) convert to 0-7 dec, no problem.
PartionTable = bit 12-14 (3-bit long) convert to 0-7 dec, no problem.
CompanyPrefix = bit 15-28 (14-bit long) convert to 0-16384 dec, no problem.
SerialNo = bit 29-66 (38-bit long) this value is bigger than 32-bit and that is my problem because the PLC-system is built to handle max 32-bit each programaccess.
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benthouse
- Posts: 31
- Joined: Tue Nov 06, 2007 3:48 pm
- Location: Europe
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by benthouse » Sat Feb 26, 2011 5:31 pm
which type of RFID reader is used?
I'm looking for readers which can be conneced to Profibus-DP directly.
For me it's only necessary to identifiactie the RFID Taf (unique) number in a PLC program.
Waiting for your answer....
Regards,
Benthouse
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Apollo11
- Posts: 4
- Joined: Thu May 06, 2010 6:46 pm
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by Apollo11 » Mon Mar 07, 2011 2:57 pm
Sorry for the late answer.
The RFID reader from a company called Vilant (
www.vilant.com).
You need for now a gateway between the reader and your profibus-system.
Everything can be deliverd by Vilant.
//Apollo11
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Coyote
- Posts: 41
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- Location: Slovenia
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by Coyote » Sun Mar 27, 2011 12:00 pm
Change the way of thinking, RFID key for sure doesn't use a CPU that is better than Siemens CPU4xx, so you can use more than one byte, dint, ... array of bits,..
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dehell
- Posts: 104
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- Location: Europe
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by dehell » Mon Mar 28, 2011 7:08 am
Hi,
Another way to solve your problem : use string (convert byte area into string)
Then, use SCL for programming with string , it is more easy...