Using 4 – 20ma inputs/outputs, Using 4 – 20 ma inputs/outputs -11, Using 4 – 20 ma inputs/outputs – Rockwell Automation 1336E IMPACT Adjustable Frequency AC Drive User Manual V 1-4.XX User Manual
Page 151

Applications
9-11
Figure 9.4
Analog Output 1 +100% Speed Indication
Using 4 – 20 mA Inputs/Outputs
The 1336 IMPACT drive provides a 4 – 20 mA input and a 4 – 20 mA
output. You can use the parameters that are available for the
4 – 20 mA input and output in the same way that you would use the
analog input and output parameters. For example, you can use a scale,
offset, and/or filter parameter to adjust the input value and a scale
and/or offset parameter to adjust the output value.
Two advantages for using the 4 – 20 mA are:
•
The current supply is regulated to adjust the voltage as needed to
keep a constant current moving through the system.
•
Noise in the system does not affect current as much as it does
voltage.
Figure 9.5 shows an example of a 1336 IMPACT drive that is used as
a master drive to control three other 1336 IMPACT drives. Notice that
you can have a maximum of three slave drives.
–100%
Base Speed
0 Speed
+100%
Base Speed
5V
0V
10V
+1024
0
–1024
+2048
+1024
0
+10V = + 100% Base Speed
+5V = 0 Speed
D
A
Digital Range
From Drive
Scaled by 0.25
0V = –100%
Offset by 5V, Adding 1024
Digital Value
Meter Voltage
% Base Speed
– 4096
– 1024
+ 1024
0
0 Volts
– 100%
0
0
+ 1024
0
5 Volts
0%
4096
+ 1024
+ 1024
2048
10 Volts
+ 100%
Par 105
Par 81
Motor
Speed
An Out 1 Value
An Out 1 Scale
Par 107
x 0.25
An Out 1 Offset
Par 106
5V = 1024
(+2048 = +10V)
+4096 (+100% Speed)
0
–4096 (–100% Speed)