So I've got a machine using a 4-20ma pressure transducer into a 12bit analog card on a s7-315
The OE transducer had to be replaced, and when we inquired with the manufacturer of the part they said that transducer was no longer available, and had been changed to ##### model which is functionally and physically the same, but has a great increase in range.
Original
0-5.2bar
newer equivalent
0-28.4bar
So the OEM used fc105 to do the scaling of the input, and even after reading the siemens description of the function im a little confused with how it was setup.
Original configuration:
PIW268
in0 =300
in1 =-300
After we replaced it with the 28.4bar newer sensor the analog input was reading in the 12XXX range at atmosphere.
I started manipulating the values in in0 and in1 to make it end up with a zero result in out4 because when the machine starts it needs to be reading atmosphere.
I ended up with
in0=27.648
in1=12.4
This may be completely wrong and I fully acknowledge that.
My problem is that I am struggling to make sense of why they did 300 to -300 in the original setup.
According to the siemens document:
After reading this I initially set the min max according to the sensor, but that didn't seem to work at all.
Any pointers or education on this would be great, thanks in advance.
The OE transducer had to be replaced, and when we inquired with the manufacturer of the part they said that transducer was no longer available, and had been changed to ##### model which is functionally and physically the same, but has a great increase in range.
Original
0-5.2bar
newer equivalent
0-28.4bar
So the OEM used fc105 to do the scaling of the input, and even after reading the siemens description of the function im a little confused with how it was setup.
Original configuration:
PIW268
in0 =300
in1 =-300
After we replaced it with the 28.4bar newer sensor the analog input was reading in the 12XXX range at atmosphere.
I started manipulating the values in in0 and in1 to make it end up with a zero result in out4 because when the machine starts it needs to be reading atmosphere.
I ended up with
in0=27.648
in1=12.4
This may be completely wrong and I fully acknowledge that.
My problem is that I am struggling to make sense of why they did 300 to -300 in the original setup.
According to the siemens document:
Configured measuring range of 4 to 20mA (0 to 5 bar)
Example:
The integer value 27648 corresponds to 20mA and thus 5 bar in this example. The integer value 0 corresponds to 4mA and thus 0 bar in this example. Therefore, you should parameterize the high limit HI_LIM to 5.0 and the low limit LO_LIM to 0.0 to obtain correct scaling.
After reading this I initially set the min max according to the sensor, but that didn't seem to work at all.
Any pointers or education on this would be great, thanks in advance.