Specifications

Altivar
®
31 Adjustable Speed AC Drives
Functions
© 2004–2005 Schneider Electric All Rights Reserved
40
4/2005
Control and reference channels
The drive receives control commands—such as forward and reverse—and
speed reference commands from the following sources:
• the logic and analog inputs
• the drive local keypad display (on ATV31••••••A drives only)
• the remote keypad display
• the serial link
— Modbus control word
— CANopen control word
You can assign control and reference sources to separate control channels
and switch between them—for example, by giving the speed reference via
the CANopen serial link but the control commands via the remote keypad
display.
NOTE: The STOP keys on the local keypad display and the remote keypad
display may retain priority. The Summing inputs and PI regulator functions
only apply to one reference channel.
Reference switching
Switching between two speed references is enabled using a logic input or a
bit in a Modbus or CANopen control word.
Reference 1 is active if the logic input (or control word bit) is at 0; reference 2
is active if the logic input (or control word bit) is at 1.
The reference can be switched with the motor running.
Connection diagram for reference switching
Summing inputs
This function sums two or three speed references from different sources.
The references can come from any of the various speed reference sources.
Example:
Reference 1 sent by AI1
Reference 2 sent by the potentiometer
Reference 3 sent by the CANopen serial link
Drive speed reference = reference 1 + reference 2 + reference 3
1
0
1
AI2
AI1
LIx 0
f (Hz)
t
t
t
Forward
or
Reverse
Example of reference switching
563544
.eps
LIx COM AI1 AI2 AI3
+ 24 V
± 10 V X-Y
+10
0
(X is adjustable from 0 to 20 mA
and Y is adjustable from 4 to 20 mA)
563545.eps
Courtesy of Steven Engineering, Inc.-230 Ryan Way, South San Francisco, CA 94080-6370-Main Office: [phone]-Outside Local Area: [phone]-www.stevenengineering.com