Operation Theorem
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4.8
Open-loop and close-loop control
This section explains the motion control algorithms provided by PCI-8136M.
There are two possible ways of control command output. One is via DAC
channel
à
analog voltage, and the other is via OUT & DIR
à
Pulse
command.
4.8.1
Open-loop control
When the OUT & DIR channel is used as motion command output, the block
diagram is as the following figure.
The pulse generated by DDA engine is directed into pulse output device. And,
according to user’s choice of pulse type, CW/CCW, Pulse/Direction, or AB
phase, pulses chains will generated from OUT & DIR channels.
4.8.2
Close -loop control
When the DAC channel is selected as motion command output, the block
diagram is as following figure.
In this mode, the pulse output channel OUT & DIR is disabled, and won’t
generate any pulse signals. The DAC output value is decided by position
error multiplied by Kp gain. Position error is calculated by accumulating DDA
pulses and subtracting encoder feedback. The Kp gain is tunable by using
software function call. This procedure is done by hardware and is always
much faster than mechanical responding. However, the reasonable Kp value
depends on specific application very much. Some try and error procedures
may be needed.
Summary of Contents for PCI-8136M
Page 1: ...PCI 8136M 6 Axis Motion Controller Card User s Guide ...
Page 2: ......
