Instruction manual

2-18 / Installation CI-ControlWaveLP
2.4.3 Analog Inputs (see Figures 2-14 through 2-17)
The Analog Input module of the FMI/OB Board is designed to support eight (8) 1-5V or 4-
20mA isolated inputs or 4-20mA loops powered from a field source. An isolated DC/DC
converter powers the ADC, instrumentation amplifier and multiplexers. Optocouplers are
used for the control circuitry.
Figure 2-14 - Analog Input Terminal Block TB3 - & Configuration Jumpers
The common mode range for the Analog Inputs is 38VDC. The input signals and on board
reference voltages are attenuated with forty to one attenuators. A low pass filter sets the
cutoff frequency to 3 Hz. Analog multiplexers select one of the eight channels or the
reference voltages. An instrumentation amplifier converts the differential signal to a single
ended signal and amplifies the signal 10X and is followed by 4X gain circuit. Four
potentiometers are required to set the 1V and 5V references and to adjust the offset and
gain of the 4X circuit.
In addition to Jumper W29, there are eight sets of configuration jumpers (W20A/W20B -
W27A/W27B) used to configure Analog Inputs, AI1 - AI8 (see Figure 2-14).