Cameron LEFM 200 - Page 16

IB0147 Rev. 08 LEFM 200 Modbus User Manual
Section 2 Page 12 December 2010
2.9.3 Analog Inputs – 200Ci Electronics Only
Inputs 3 and 4 are not available on the 220Ci, 240Ci, and 280Ci. Further, Analog input number
1 is the only analog input available to the user. Analog input 2 is dedicated to a 4 wire RTD for
the Meter Body Temperature. For Analog input 1, the following table is used to scale the input.
Variable Description – Analog
Input Number 1 Only Name
Holding
Register
Address
Minimum Voltage for Input X1
104
Minimum Engineering Value at
Minimum Voltage
Y1 106
Maximum Voltage for Input X2
108
Maximum Engineering Value at
Maximum Voltage
Y2
110
Using the above coefficients, the transmitter does a linear scale:
Analog Input (engineering units) = Y1 + (Analog Input-X1)*(Y2-Y1)/(X2-X1)
Since only one analog input is available to the user in the 200Ci electronics, that input can be
mapped to any of the possible inputs (e.g., fluid temperature, pressure, or density). Inputs not
mapped to analog input 1, are mapped either to a Modbus input or a default value according to
the following table:
Setup Variable
Holding Register
Variable Definition Address Comment
Fluid Pressure Integer 3325 If set to 1, use Analog input number 1
If set to -1, use Modbus input
If set to 0, use default value in setup file
Fluid Temperature Integer 3326 If set to 1, use Analog input number 1
If set to -1, use Modbus input
If set to 0, use meter body temperature
Density Integer 3327 If set to 1, use Analog input number 1
If set to -1, use Modbus input
If set to 0, use LEFM calculated density