sparkotronic Posted January 18, 2007 Report Posted January 18, 2007 Hi, I'm looking for a bit of help with a machine modification that I'm about to try. I am looking to control vacum pressure on a filling machine. I idealy want to use a 4-20mA pressure transducer connected to a Siemens 314 PLC. The current system has a TP170 HMI and I want to display the actual pressure on this. The question is, how do I go about scaling the raw analog value so that it will display it in ib/in2 or bar.? I will also need to be able to adjust the upper and lower limits via the TP170 so will the scalling cover this too? Thanks in advance, Colin Quote
JesperMP Posted January 18, 2007 Report Posted January 18, 2007 Hi Colin In the standard library, under TI-S7 Converting Blocks, you will find FC105 SCALE. Select it and hit F1 to get help on the usage. You can dsiplay the value from the OUT pin and set the values on the HI_LIM and LO_LIM pins on the TP170 panel. Quote
sparkotronic Posted January 19, 2007 Author Report Posted January 19, 2007 Cheers Jesper! I'll give that a go on Monday and let you know how I get on. I find this forum is a great source of info and help. Regards, Colin Quote
sparkotronic Posted June 11, 2007 Author Report Posted June 11, 2007 Hi Sometimes I feel as thick as a plank! I'm struggling with the FC105 thingy. Would the following code convert a 4-20mA input to 0-10? L PIW 500 ITD DTR L 1.000000e+001 *R L 2.764800e+004 /R RND T DB6.DBW4 This might sound stupid as well....but is the e+000 bit on a real number for the position of the decimal place? I've got it working with just using the integer value, but it would be nice to display the vaccum in bars. Regards, Colin Quote
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