Allen-Bradley PowerFlex 70

Input Modes 2-109
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