GPIO Menu

The GPIO menu allows you to program the hardware parallel inputs and outputs used to remotely control certain PDM II functions. Livewire GPIO is configured in the Configuration page of the web-based user interface.

The inputs and outputs are opto-isolated to easily interface with external equipment. A +5V supply and ground are available on the DB-15 connector for simple remote controls using pushbuttons and LED status readouts with a maximum total current draw of 200 mA. The supply is protected by an internal, self-resetting thermal circuit breaker; should the breaker trip, power the unit off for several minutes to reset it.

Inputs require at least 6mA from the input common pin and the individual input circuit pin. Outputs can carry up to 25 mA and up to 30VDC per channel between the output common pin and the individual output circuit pin.

If the output signal is a pulse, its opto-isolator will turn on for 250ms. This can be adjusted to between 100ms and 1000ms in the Configuration tab of the web GUI.

The pin-out of the DB-15 connector is as follows:

Pin Number	Function
1	GPO 1
2	GPO 2
3	GPO 3
4	GPO 4
5	GPO 5
6	Not used
7	GPO Common
8	GPI Ground
9	GPI Power
10	GPI Common
11	GPI 1
12	GPI 2
13	GPI 3
14	GPI 4
15	GPI 5

GPIO Enable

Hardware GPIO can be enabled or disabled in the GPIO Enable menu. When enabled, the rear panel DB-15 port is active.

GPIO Inputs

Each of the five input pins can be assigned a PDM II function. The same function can be assigned to multiple input pins.

GPIO inputs can either be triggered or level-sensitive. Triggered (or edge-sensitive) inputs cause something to happen when the input becomes active. Level-sensitive inputs cause a state to be true as long as the input is active. The CueX and Bypass inputs are triggered; all others are level-sensitive.

Input functions include:

None: No function assigned.
Build: Front panel Build button.
Exit: Front panel Exit button.
Cough: Front panel Cough button.
Bypass: Front panel Bypass button.
CueX: Applies to Cue 1 through Cute 8 functions.
- Cues are linked to incoming audio samples and stay with the sample regardless of how much time manipulation is being applied, allowing them to be passed along to other devices.
- Cue marks generate a 250ms trigger when they are reached.
- Cues typically indicate important programming events such as commercials or news breakaways. For example, if the network provides a contact closure to trigger a local break and its input is assigned to a Cue function, PDM II will generate a corresponding Cue output when that sample is reached in order to trigger external equipment to start the break.
Flag: Applies to Flag 1 through Flag 8 functions.
- Like cues, flags also indicate an important programming event.
- Flag marks record a continuous logic input, and their output reflects that logic state when the appropriate audio sample reaches the PDM II's output
- Flags can be used to activate a skimmer or logging recorder by connecting a mic's tally signal to the input and using its output to keep the recorded turned on whenever the mic is open, regardless of how much delay is used.
Utility: Applies to Utility 1 through Utility 4 functions. Allows you to have input closure immediately cause and output closure with no delay. This is useful for implementing or diagnosing end-to-end relay logic when connecting PDM II to other devices.
Pause: Suspends delay or exiting when active.

GPIO Outputs

Each of the five output pins can be assigned a PDM II function.

GPIO outputs can either be triggered or level-sensitive. Triggered (or edge-sensitive) outputs emit a pulse when something happens (the default pulse length is 250ms, but can be adjusted in the "Hardware GPIO" section of the web UI Configuration page). Level-sensitive outputs indicate that a state is true as long as the output is active. The CueX and various XXXTrig outputs are triggered; all others are level-sensitive.

Output functions include:

None: No function assigned
BuildTrig: A pulse indicating the delay has started building
FullTrig: A pulse indicating the delay buffer has become full.
DumpTrig: A pulse indicating a Dump has occurred.
EmptyTrig: A pulse indicating the delay buffer has been emptied.
Cue: Pulse from Cue 1 through Cute 8 functions. See the GPIO Inputs section for a full explanation of Cues.
BuildLamp: Duplicates the front panel "Build" button lamp. Note that all "Lamp" pulses cause a "Low" state when the lamp is on, a "High" state when the lamp is off, and cycles on and off when the lamp is flashing.
ExitLamp: Duplicates the front panel "Exit" button lamp.
DumpLamp: Duplicates the front panel "Dump" button lamp.
CoughLamp: Duplicates the front panel "Cough" button lamp.
Bypass: Indicates the unit is currently in bypass.
Building: Indicates the unit is currently building a delay buffer.
Exiting: Indicates the unit is currently exiting delay.
DelayFull: Indicates the delay buffer is full and the maximum delay has been reached.
DelaySafe: Indicates there is a sufficient buffer for at least one delay dump.
DelayUnsafe: Indicates there is not enough audio in the buffer to perform a full delay dump.
DelayEmpty: Indicates the delay buffer is completely empty.
Muted: Indicates the unit is currently muted.
Flag: Applies to Flag 1 through Flag 8 functions. See the GPIO Inputs section for a full explanation of Flags.
Util: Applies to Utility 1 through Utility 4 functions. See the GPIO Inputs section for a full explanation of Utilities.
StreamFail: Indicates the currently-selected digital input has failed.

GPIO Test

The GPIO Test screen lets you verify that hardware GPIO connections and external remotes are properly wired.

The "Ins" line shows the current input state of the five hardware GPIs. The "Outs" line allows you to set the five hardware GPOs to any desired value.

Note - If the display shows "Disabled", then hardware GPIP is disabled. It can be enabled in the GPIO menu.

When you leave the Test screen, all outputs will be restored to their configured values.