Controlling Array Virtual Channels - Polycom SoundStructure C16 Design Manual

set digital_gpio_state "Logic Output Example" 1
Additional information about using logic pins may be found in Appendix A.

Controlling Array Virtual Channels

Multiple logic pins may be associated together with a control array virtual channel. Control array virtual
channels are created by one or more logic input or logic output pins. Once a control array channel is defined,
the value of the group of pins can be queried or set using the digital_gpio_value command.
The value of the digital control array is the binary sum of the individual logic pins. For example, if a control
array virtual channel is defined with digital output pins 2, 3, and 4, then the value of the control array channel
is in the range of 0 to 7 with physical logic pin 4 as the most significant bit and physical logic pin 2 as the
least significant bit.
As an example, consider a control array named "logic array" that uses physical logic input pins 2, 3, and 4
that is created with the following syntax:
vcdef "logic array" control_array digital_gpio_in 2 3 4
which returns the command acknowledgment:
vcdef "logic array" control_array digital_gpio_in 2 3 4
In this example, three input pins have been specified with pin 2 first and pin 4 listed last. The value of the
digital input array can be queried using the get action:
get digital_gpio_value "logic array"
val digital_gpio_value "logic array" 7
The value of the logic array depends on the value of the individual logic input pins 4, 3, and 2. A logic pin
has a value of 0 when that the pin is shorted to ground and a value of 1 when that pin is open.
The order that the pins are listed in the control array definition is defined so that the last pin specified is the
most significant bit and the first pin specified is the least significant bit. For the example above where the
control array was defined with pins 2 3 4, the 3-bit value is formed by using pin 4 as the most significant bit,
pin 3 as the next bit, and pin 2 as the least significant bit.
Control Array and Logic Input Pin Values
Control Array Value
7
6
5
4
3
2
1
0
In the above table, if all the pins are open, the get command described above returns the value 7. If pin 2 is
shorted to ground (value of 0), the value of the get command is 6 and so forth.
Polycom, Inc.
Pin 4 Pin 3 Pin 2
1 1 1
1 1 0
1 0 1
1 0 0
0 1 1
0 1 0
0 0 1
0 0 0
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