SCC-AI Series Isolated Analog Input Modules User Guide
8
ni.com
5.
Using your software, have the E/M Series DAQ device read the desired
channel on the SCC-AI and record the value.
6.
Input 0 VDC to the SCC-AI.
7.
Use the E/M Series DAQ device to read that channel and record the
value.
8.
Subtract the values read (
first reading
–
second reading
).
9.
Adjust the trimpot labeled
Gain
located on the top of the SCC-AI. If
the value you obtained in step 8 is less than the input voltage, turn the
trimpot clockwise to increase the gain. If it is greater than the input
voltage, turn the trimpot counterclockwise to decrease the gain.
10. Repeat steps 4 through 9 until the difference you get in step 8 equals
the Input Voltage Required value shown in Table 2; in this example the
value is 8 V using an SCC-AI03.
For example, assume that you have an SCC-AI03 module. You first connect
8 VDC to the input of CH (
X
). The E/M Series DAQ device reads 8.05 V
as the SCC output. You then connect 0 VDC to the input of CH (
X
) and the
E/M Series DAQ device reads –0.01 V as the SCC output. You subtract
these readings, 8.05 – (–0.01)
=
8.06, getting a difference of 8.06 V.
Because this difference is not equal to 8 V, you must adjust the gain trimpot
and repeat the procedure until the difference in outputs equals 8 V.
Note
In this example there can be an offset voltage such that the final readings are 8.01 V
and 0.01 V for a difference of 8 V. The gain trimpot adjusted in step 9 of the previous
procedure adjusts only for gain errors and does not compensate for this offset voltage.
Offset Voltage Adjustment
Complete the following steps to adjust the offset voltage of the SCC-AI:
1.
Select the desired SCC-AI channel on the E/M Series DAQ device.
2.
Set the gain on the E/M Series DAQ device so that the input range
is ±10 V.
3.
Connect the screw terminals of your desired channel on the SCC-AI
together.
4.
Using your software, have the E/M Series DAQ device read the
channel.
5.
If the value read is not equal to 0.00 V, adjust the appropriate trimpot
located on the top of the SCC-AI, labeled
Offset
. Turn the trimpot
clockwise to increase the offset.
6.
Repeat steps 4 and 5 until the voltage read in step 4 equals 0.00 V.
Summary of Contents for SCC-PWR01
Page 1: ...SCC PWR01...
