User's Manual

NXC-VAI4 Analog Voltage Control Card
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NetLinx Cardframe, Control Cards, and NetModules - Operation Reference Guide
NXC-VAI4 Send_Commands (Cont.)
Command Description
GD Sets the maximum allowable deviation of final servo position when executing the GL command. The
level of the specified input or output will only be reported when a change greater than this deviation
occurs. Deviation 0 is most accurate, but can have some oscillation, so the default is 2, i.e. the position
as read at corresponding input I/O <x+4> can be within +/-2 from the specified position.
Syntax:
SEND_COMMAND <DEV>,'G<I/O>D<DEVIATION>'
Variables:
I/O: Any input or output ('1', '2', '3', '4', '5', '6', '7'. '8')
DEVIATION: Number between 0 and 127 (default = 2)
Example:
SEND_COMMAND <DEV>,'G1D10'
Sets I/O 1 servo output to 10.
GL This command puts the card in servo (positional) control mode. The range of the position is 0-255 (if AD
MODE is set to '8'), or 0-65535 (if AD MODE is set to '10'). See AD MODE earlier in this section for
details.Position 0 is the low end of the potentiometer (lowest voltage); position 255 (or 65535) is the
high end of the potentiometer (highest voltage) with 128 (or 32768) as the middle of the range.
Syntax:
SEND_COMMAND <DEV>,'G<OUTPUT>L<POSITION>'
Variables:
I/O: Any Output ('1', '2, '3', 4')
POSITION: Number between 0-255 or 0-65535 (depends on AD MODE)
Example (Assuming the current position is 0):
SEND_COMMAND <DEV>,'G1L255'
Sets Output 1 to "CURRENT OUTPUT 1 SPEED" (positive) and waits until Input 1 reads within
"OUTPUT 1 MAXIMUM DEVIATION" of 255 and then resets the output to zero speed. The speed output
may have a more complex profile than as set by the "GAS" command.
GS Sets the speed variable to be used for future positional (GL) commands. The change of speed takes
place immediately even if a positional change operation is currently in progress. The voltage output for
speed 0 (i.e. when no motion is desired) is at the mid-point between the Min and Max output voltages.
The positive speed 127 is the max and negative speed 127 is the min. Other speeds are scaled
proportionately.
Syntax:
SEND_COMMAND <DEV>,'G<OUTPUT>S<SPEED>'
Variable:
I/O: Any Output ('1', '2, '3', 4')
SPEED: A fixed output value in the range of 0 (slowest)-127 (fastest - default)
Example:
SEND_COMMAND <DEV>,'G1S64'
Sets Output 1 servo speed to 64 (50%).
LEVOFF The NXC-VAI4 will not transmit any level value messages after the receipt of this command until the
receipt of the LEVON command.
Syntax:
SEND_COMMAND <DEV>,'LEVOFF'
LEVON The NXC-VAI4 will not transmit any level value messages until after the receipt of this command. This
command is sent automatically when the CREATE_LEVEL command is executed.
Syntax:
SEND_COMMAND <DEV>,'LEVON'