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# Scaling in FX 3GE PLC

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Can anybody please help me? I have FX 3GE plc and reading (4-20) mA signal using built in analog input as 0 to 3200 counts. I want to display this counts as (0-1500) RPM. I searched the manuals, SCL and SCL2 instruction will work only in FX 3U PLC not in FX 3GE plc. Please help me to scale the values. Thanks in advance With Regards Joshua jo2ham@yahoo.co.in

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You'll have to do old fashioned math. Simplest way is to multiply your input by 1500, then divide the 32-bit result by 3200: MUL D8260 K1500 D100 DDIV D100 K3200 D100

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As an alternative... Y=X*1500/3200=X*15/32=X*(16-1)/32=(X/2)-(X/32) -> Y=X/2; Z=Y/16; Y=Y-Z DIV D8260 K2 D100 DIV D100 K16 D101 SUB D100 D101 D100 or Y=X*1500/3200=X*15/32=X*(16-1)/32=16*(X-(X/16))/32=(X-(X/16))/2 -> Y=X/16; Y=X-Y; Y=Y/2 DIV D8260 K16 D100 SUB D8260 D100 D100 DIV D100 K2 D100 The last calculation will use and occupy only two data registers D100&D101. Edited by Inntele
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Thank you so much. It's working. With Regards Joshua

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This Block will calculate it for you, handy to have in the library