Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 142)

142 Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014
Chapter 3 Component Definition and Maintenance
Current Loop Transmitter
The current loop transmitter will transmit 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 PowerFlex 7000 transmitter can drive a receiver with an input
resistance up to 625 .
Figure 114 shows a block diagram of the transmitter.
Figure 114 - 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 20
(+ connection) and either pins 18, 19, 21 (- connection).
The recommended connection is shown above. 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.
5V
DSP
FPGA
#
ŀ
Isolated
DC/DC
Converter
+15V
+15V
D/A
Current
Boost
Optical
Interface
20
18
19
21
IFM