Emerson FB1200 - Analog Inputs

Emerson FB1200 Flow Computer Instruction Manual
D301782X012
March 2019
I/O Configuration and Wiring 55
3.1 Analog Inputs
The flow computer includes two on-board channels you can individually configure as either analog
inputs (AI) or analog outputs (AO). In addition, if you purchased the optional 6-channel expansion I/O
board, there are two additional channels you can individually configure as either AIs or AOs.
Note
No external resistor is required for a current (mA) device. You can apply a 250 ohm resistor using
analog input configuration selections in FBxConnect.
When configured as analog inputs, the channels have the following characteristics:
Table 3-1: Analog Input Characteristics
Type
Number Supported
Characteristics
Analog
Input
(AI)
0 to 4 as follows:
▪
1 or 2 non-isolated channels on CPU
board (AIAO1 and AIAO2) always
present. You can configure one, both,
or neither as AIs.
▪
1 or 2 additional non-isolated channels
on optional 6-channel expansion I/O
board (AIAO3 and AIAO4). If present
you can configure one, both, or neither
as AIs.
▪
4 to 20 mA range (@24Vdc), or 1 to
5Vdc
▪
Over range for calibration purposes:
3.2 to 20.8 mA or 0.8 to 5.2 Vdc
▪
Externally powered
▪
Factory calibrated (re-calibration is
unnecessary for at least 3 years)
▪
Signal conditioning
▪
When you configure a channel as an
AI it cannot be used as an AO
3.1.1 AI Wiring
Wire analog inputs as shown in the following figures.
Note
Figures 3-4 and 3-5 show analog input wiring for AIAO2. AIAO1 and AIAO2 share the same GND
terminal.