Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 375)

Component Definition and Maintenance 6-85
7000 “B” Frame 7000-UM150I-EN-P – June 2013
Analog Inputs and Outputs
The PowerFlex 7000 “B” Frame offers one isolated process current
loop transmitter and one isolated process current loop receiver,
embedded into the control. These are accessible on the CIB.
Each of these can be configured independently as either 0-20mA or
4-20mA. (Refer to Programming Manual).
The following information will show the connections for each.
Current Loop Transmitter
The current loop transmitter will transmit either 0-20mA or 4-20mA
output to an external receiver. The loop compliance on the
transmitter is 12.5V. Loop compliance is the maximum voltage at
which a transmitter can generate to achieve the maximum current
and is usually a function of the power supply voltage. Therefore, the
transmitter can drive a receiver with an input resistance up to 625
ohms. The figure below shows a block diagram of the transmitter.
DSP
FPGA
Optical
Interface
D/A
Current
Boost
Isolated
DC/DC
Converter
+15V
+5V
1
2
3
4
J4A
+15V
DSP
FPGA
Optical
Interface
D/A
Current
Boost
Isolated
DC/DC
Converter
+15V
+5V
1
2
3
4
J4A
+15V
Figure 6.61 – Process Loop Transmitter Block Diagram
This type of transmitter is known as a 4-wire transmitter, and will
“sink” current from a receiver. The receiver is connected by two wires
only from pins 1 (+ connection) and either pins 2, 3, 4 (- connection).
The recommended connection is shown below. The type of shielded
cable used is application specific and is determined by the length of
the run, the characteristic impedance and the frequency content of
the signal.