Polycom SoundStructure C16 Design Manual page 70

Design Guide for the Polycom SoundStructure C16, C12, C8, and SR12
3 - 22
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 will be in
the range of 0 to 7 with physical logic pin 4 as the most significant bit and phys-
ical 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 will return the command acknowledgement:
vcdef "logic array" control_array digital_gpio_in 2 3 4
In this example 3 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 will depend on the value of the individual logic
input pins 4, 3, and 2. A logic pin will have 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 will be 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 Value
7
6
5
4
3
2
1
0
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