Rockwell Automation 20B PowerFlex 70, PowerFlex 700 Reference Manual - Manual (Page 109)

Input Modes
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013 109
Input Modes
The PowerFlex family of drives does not use a direct choice of 2-wire or 3-wire
input modes, but allows full configuration of the digital I/O. As a means of
defining the modes used, consider the following:
2-Wire Control
This input mode is so named because it
only utilizes one device and 2 wires to
control both the Start (normally
referred to as “RUN” in 2-wire) and Stop
functions in an application.
•
A maintained contact device, such
as a thermostat, for example,
closes its contact to Run the drive
and opens to Stop the drive.
•
In other applications, the
maintained device (such as a limit
switch), can directly control both
Run/Stop and direction control…
•
Or, a combination of the two may
be desirable.
3-Wire Control
This input mode utilizes 2 devices
requiring 3 wires to control the Start
(proper term for 3-wire) and Stop
functions in an application. In this case,
momentary contact devices, such as
pushbuttons are used.
•
A Start is issued when the Start
button is closed, but unlike 2-wire
circuits, the drive does not Stop
when the Start button is released.
Instead, 3-wire control requires a
Stop input to Stop the drive.
•
Direction control is accomplished
either with momentary inputs…
•
Or, with a maintained input.
Run/Stop
PWR
STS
PORT MOD NET A NET B
Run Forward
Run Reverse
PWR
STS
PORT MOD NET A NET B
Run
PWR
STS
PORT MOD NET A NET B
Forward/Reverse
Stop
Start
PWR
STS
PORT MOD NET A NET B
Stop
Start
Forward
Reverse
PWR
STS
PORT MOD NET A NET B
Stop
Start
PWR
STS
PORT MOD NET A NET B
Forward/Reverse