Copley Controls Accelnet Plus BEL Series User Manual page 25

Accelnet & Stepnet Plus Panels User Guide
O
FFSET
To remove the effects of voltage offsets between the controller and the drive in open loop systems, CME
provides an Offset parameter and a Measure function. The Measure function takes 10 readings of the analog
input voltage over a period of approximately 200 ms, averages the readings, and then displays the results. The
Offset parameter allows the user to enter a corrective offset to be applied to the input voltage.
The offset can also set up the drive for bi-directional operation from a uni-polar input voltage. An example of
this would be a 0 to +10 Vdc velocity command that had to control 1000 rpm CCW to 1000 rpm CW. Scale
would be set to 2000 rpm for a +10 Vdc input and Offset set to -5V. After this, a 0 Vdc input command would
be interpreted as -5 Vdc, which would produce 1000 rpm CCW rotation. A +10 Vdc command would be
interpreted as +5 Vdc and produce 1000 rpm CW rotation.
M
ONITORING THE
The analog input voltage can be monitored in the CME control panel and oscilloscope. The voltage displayed
in both cases is after both offset and deadband have been applied.
A C
NALOG OMMAND IN
The Accelnet & Stepnet Analog Position command operates as a relative motion command. When the drive is
enabled the voltage on the analog input is read. Then any change in the command voltage will move the axis
a relative distance, equal to the change in voltage, from its position when enabled.
To use the analog position command as an absolute position command, the drive should be homed every time
it is enabled. The Homing sequence may be initiated by CAN, ASCII serial, CVM or CPL Indexer program
commands.
200
100
Dead Band
0
-100
-200
-200
A C V
NALOG OMMAND
P M
OSITION ODE
-100 0 100
Input
OLTAGE
16-01339 Rev 07
200