Calrec Hydra2 Fixed Format GPIO Card (SW5739)

Calrec Hydra2 GPIO Card (SW5739)

The SW5739 is an optional GPIO card that can be fitted in most fixed format I/O boxes. GPIO are General Purpose Inputs and Outputs. GPIO are often used to connect different pieces of equipment together to allow a function on one to be triggered by a selection on the other, for example, to make a CD player start playing automatically when its fader is opened on the mixing console or to light an “on-air" sign when a mic fader is opened

Currently, the only fixed format I/O box types that can NOT be fitted with a GPIO card are the 1U MADI units, and the rear interfacing AES unit, due to physical space limitations. All other fixed format I/O units available can have the GPIO option fitted. Different GPIO cards, with a different connector and pin-out, are available for modular I/O racks.

One SW5739 card can be fitted in each compatible I/O box, providing 8 inputs, and 8 outputs per unit. Multiple I/O boxes can be fitted with GPIO cards to make up the total quantities of GPIO required in each location.

Fixed format I/O boxes with GPIO cards fitted have D-type connectors on the rear panel. Units without a GPIO card will have these connectors blanked off. The function assigned to each GPIO input and output is selected from any control surface on the network. GP output functions include fader starts, assignable button presses, error alerts, and more. GP input functions include path Cut/On, Auto-fader triggers and more.

Please refer to the console Operators Manual for details on GPIO assignment.

Wiring Information

(click image to enlarge)

GP outputs

Relays are used for GP outputs. All 3 relay contacts are made available on the GP output connector to provide flexibility in use—they can be wired to produce a standard closure when activated, to produce a default closure that becomes open when active, or to pass a ground or voltage that is made or broken when activated.

Having all 3 contacts also allows audio or other signals to be fed through the relay and switched by GPIO control if required. The Common pin is always connected to one of the other two pins by the relay—when the relay is NOT activated, Common is connected to the Normally Made pin. When the relay becomes active (the assigned GP function is triggered), the Common pin becomes connected to the Normally Open pin. To create a dry closure, Some typical wiring examples are shown on this page.

GP inputs

Opto-isolated inputs allow for mixing console functions to be triggered remotely by other equipment. Applying voltage across the + and - pins of an opto will trigger it. If using a dry (no voltage) closure as a trigger, one side of the closure should be wired to one of the opto's pins, the other side of the closure should be wired to ground, and the other side of the opto should be wired to +ve voltage. Both voltage and ground should be sourced from the GPIO card itself where possible.

If the 3rd party kit sends a single logic line, as opposed to a closure pair, both pieces of equipment will need to share the same ground reference, or +ve voltage will need to be supplied by the 3rd party kit. Common wiring examples are shown on this page.