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SIMATIC TDC, FM458, T400

FM458 SSI encoder connection

Thread Starter: GreenRay   Started: 5/15/2012 5:42 PM   Replies: 3

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  5/15/2012, 5:42 PM
GreenRay
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Hello,
The task of connecting the emulator of the SSI probe FM458. RS485 of emulator provides an output voltage with the difference only 2 volts.
After connecting to the M458 on the line with the data appears offset from zero, which causes the logic 0 corresponds to 0 volts and a logic 1 corresponds to 2 volts. How do I get when connecting the FM ± 1 volt?

http://www.wiki-kollmorgen.eu/wiki/DanMoBilder/file/pdf_archiv/drives_AC_digital/SERVOSTAR/SR300/2011-09/sr300_e.pdf

This is a reference to the description of servoamplifier, which emulates the SSI encoder. On page 86 a description of the encoder emulation.

Thanks.
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  5/16/2012, 9:08 AM
KSN
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Hello.
Did you try to connect your emulator to the EXM438 and read its data in CFC at block AENC?
RS-485 regulates only difference between DATA+ and DATA- voltages of encoder, that must be >200mV for 1 and <-200mV for 0.
But note that EXM438 supports only 13 or 25 bit encoders +parity.
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Thank you for this post from:
miami
  5/17/2012, 4:53 PM
GreenRay
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Thank you for reply. The problem was solved by replacing the RS485 chip on the same.
topic can be closed.
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  8/16/2012, 6:08 AM
AjayG
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KSN wrote:
Hello.
Did you try to connect your emulator to the EXM438 and read its data in CFC at block AENC?
RS-485 regulates only difference between DATA+ and DATA- voltages of encoder, that must be >200mV for 1 and <-200mV for 0.
But note that EXM438 supports only 13 or 25 bit encoders +parity.


Dear KSN i have used 24bit encoder + parity with EXM438 and it works fine. EXM438 accepts 13 to 25 bit encoder but in help file of AENC block it is clearly mentioned 13 or 25 bit encoders.
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