11/12/2012 11:08 PM | |
Joined: 9/27/2006 Last visit: 9/24/2024 Posts: 12282 Rating: (2685)
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Hello soussia; Your CPU 313C has5 analog inputs,four of which can be wired for 0-20 mA signals, and are accessible at addreses PIW 752 (channel 0), PIW 754 (Channel 1), PIW 756 (Channel 2)and PIW 758 (Channel 3); PIW 760 (Channel 4)is reserved for temperature measurement. The attachment contains an extract from the following manual, showing how to connect the 4 analog input channels. Use the I and C connections for current reading; connect all analog commons to Mana (pin 20) and short all unused channels to their common; this will help reduce noise on the analog channels. SIMATIC S7-300 CPU 31xC and CPU 31x: Technical specifications Hope this helps, Daniel Chartier |
Last edited by: dchartier at: 11/12/2012 11:09 PM |
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11/13/2012 6:05 PM | |
Posts: 63 Rating: (1) |
I changed it but the same problem. what can I do? |
11/13/2012 10:03 PM | |
Joined: 9/27/2006 Last visit: 9/24/2024 Posts: 12282 Rating: (2685)
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Hello soussia; It would be more efficient for you to read an explanatoion of how a scaling function works before we continue on this subject. I suggest you read the following FAQ, especially the quote extracted from it (an example of a pressure measurement): How and for which analog measurements can you use the function FC105 "SCALE" to convert the integer values (INT) into real number values?
So for your application set the low limit of your FC 105 at 0,0, and the high limit at 50.0. This way you are establishing your range in Hz (0 to 50) linked to your 0-20 mA signal. 0 mA/ decimal 0will show 0 (Hz) at the output of FC 105, 20 mA/ decimal 27648will show 50 (Hz), 10 mA/ decimal 13824will show 25 (Hz). You can then use the output address of the FC 105 to display on the HMI screen the Hz value of your drive. Hope this helps, Daniel Chartier |
This contribution was helpful to1 thankful Users |
11/16/2012 6:08 PM | |
Posts: 63 Rating: (1) |
thank you very much Daniel |
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