Cameron LEFM 200 - Analog Outputs

IB0147 Rev. 08 LEFM 200 Modbus User Manual
Section 3 Page 22 December 2010
Using the above coefficients, the transmitter does a linear scale:
Analog Input (engineering units) = Y1 +(Analog Input-X1)*(Y2-Y1)/(X2-X1)
For example, for a 100 RTD (-100 to 100°C), 0 volts represent -100°C and 5 volts represents
100°C.
Holding Register Address
Variable Description Name
Meter Body
Temp Input1
Pressure
Input 2
N/A
Input 3
N/A
Input 4
Minimum Voltage for Inputs X1(j) 104 112 120 128
Minimum Engineering Value at
Minimum Voltage
Y1(j) 106 114 122 130
Maximum Voltage for Inputs X2(j) 108 116 124 132
Maximum Engineering Value at
Maximum Voltage
Y2(j) 110 118 126 134
3.6 Analog Outputs
Output Scaling B1, A1, B2, A2
B1/B2 are in engineering units and A1/A2 are in counts (0 for minimum range, 65535 for
maximum range).
Analog Output (counts) = A1 +(analog engineering units-B1)*(A2-A1)/(B2-B1),
Default Outputs
Output 1 Flow,
The following table defines addresses for the Analog Output setups. The variables are entered as
Floats, however, the counts values are limited to integers. The equation used is as follows:
Analog Output(i) (counts) = B1 +(Output(i)-A1)*(B2-B1)/(A2-A1)
Where:
65535 is full scale (i.e., 20 mA for a 4-20 mA output)
0 is minimum scale (i.e., 4 mA for a 4-20 mA output)
Holding Register Address
Variable Description Name Output1 Output 2 Output 3 Output 4
Minimum Engineering Value A1(j) 136 144 152 160
Minimum Count Value B1(j) 138 146 154 162
Maximum Engineering Value A2(j) 140 148 156 164
Maximum Count Value B2(j) 142 150 158 166