ABB OPT-MF-001, User Manual

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MN1949WEN Input / Output 3-3
3.1.2 Analog inputs
 Four independent differential inputs.
 Voltage range: ±10 V.

Resolution: 16-bit (i.e. theoretical resolution ±305 µV).

Input impedance: >120 k
Ω
.
 Sampling frequency: 1 kHz.
Each analog input can be connected as either a differential or a single ended input as shown
in Figure 3-4. The analog inputs are not optically isolated from internal power rails, so care
must be taken to avoid earth/ground loops and similar associated problems. The analog
inputs pass through a differential buffer and second order low-pass filter with a cut-off
frequency of approximately 1 kHz. To minimize the effects of noise, the analog input signal
should be connected to the system using an individually shielded twisted pair cable with an
overall shield. The overall shield should be connected to the chassis at one end only. No
other connection should be made to the shield.
Figure 3-3: AIN8/16 analog input circuit
When the MotiFlex e 100 is connected to Mint WorkBench, the analog input value (expressed
as a percentage) can be viewed using the Spy window's Monitor tab. Alternatively, assuming
the card is mounted in slot 1, the command
Print ADC(8)
can be used in the command
window to return the value of analog input 8 (and similarly
Print ADC(9)
,
Print
ADC(10)
,
Print ADC(11)
for the other inputs). See the Mint help file for details.
AIN8/16-
10k
OPT-MF-001 Analog I/O
Mint
ADC(8)
ADC(16)
±100%
120k
+15 V
-15 V
11
24
12
10k 120k
AIN8/16+
AGND
-
+
Internal
reference
Low pass
filter & level
correction
or