+
External 24Vdc
Power Supply
_
Voltage
8
+
_
Vloop
7 6 5 4 3 2 1
GND012345
12304
Current
P10 - Analog Inputs
+
_
PWR
Voltage O/P
COM
PWR
Current O/P
COM
J1 J2 J3 J4 J5
Figure 4: Analog Input Wiring
5.3 Analog Input Mode Jumpers
Channels 0 through 4 can be user configured for either voltage or current operation, using jumper
links. Refer to Figure 2: SCADAPack 350 Board Layout for the location of the analog input mode
selection jumpers. A sample illustration of the analog input mode selection using jumpers J1-J5 is
given in Figure 4: Analog Input Wiring. A jumper link installed in the Current position of the
header results in a 250Ω resistor across the appropriate analog input. A jumper link installed in the
Voltage position of the header results in a high impedance analog input.
5.4 Analog Inputs Data Format
The I/O analog inputs have a 16-bit, unipolar, analog to digital (A/D) converter that measures input
voltages from 0 to 10V. The analog inputs are factory calibrated to scale the data and represent it
with a 15 bit unsigned number.
When an analog input is configured for voltage mode, 10V input is represented with 15 bits of data.
The input resolution is 0.305mV/count.
When an analog input is configured for current mode, 20mA input is represented with 14 bits of
data. There is 100% over range. The input resolution is 1.22µA/count.
Channel 5 analog input is configured for voltage mode only. 32.768V is represented with 15 bits of
data. The input resolution is 0.001V/count.
The following table shows the A/D output value for several input signals.
Current
Channel 0-4
Voltage
Channel 0-4
Voltage
Channel 5
A/D Output
0mA 0V 0V 0
1.22µA 0.305mV 0.001V 1
4mA 1.0V 3.277V 3277
10mA 2.5V 8.192V 8192
20mA 5.0V 16.384V 16384
39.999mA 9.9997V 32.767V 32767
SCADAPack 350 Hardware Manual
February 14, 2007
18
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