Analog Input Mode Jumpers; Analog Inputs Data Format; Figure 4: Analog Input Wiring - Control Microsystems SCADAPack 350 Hardware Manual

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
0mA
1.22µA
4mA
10mA
20mA
39.999mA
SCADAPack 350 Hardware Manual
February 14, 2007
+ PWR
Voltage O/P
+
_
External 24Vdc
COM
Power Supply
_
+
_
8 7 6 5 4 3
Vloop GND 0 1 2 3
P10 - Analog Inputs
0
Current
Voltage
J1 J2 J3 J4 J5

Figure 4: Analog Input Wiring

Voltage
Channel 0-4
0V
0.305mV
1.0V
2.5V
5.0V
9.9997V
PWR
Current O/P
COM
2 1
4 5
1 2 3 4
Voltage A/D Output
Channel 5
0V 0
0.001V 1
3.277V 3277
8.192V 8192
16.384V 16384
32.767V 32767
18