MADI Outputs
The 64 de-embedded audio channels are also available as MADI (Multichannel Audio Digital Interface), in both co-axial and optical formats. The MADI bit stream contains all 16 channels from all four SDI inputs. The channel numbering within the MADI bit stream is one-to-one, i.e., Channel 1 of SDI 1 becomes MADI Channel 1, Channel 2 of SDI 1 becomes MADI Channel 2, and so on for the remainder of SDI 1’s audio channels. Then Channel 1 of SDI 2 becomes MADI Channel 17, and the cycle repeats. If less than four SDI inputs are in use, the
MADI bit stream time slots corresponding to the unused inputs will simply contain all zeroes.
The co-axial MADI output is on a BNC socket, and is compliant with AES10id- 2008. The characteristic impedance is 75 , at a nominal data rate of 125Mbps. Transmission distances up to 50 m are generally achievable.
The same bit stream is available in optical format on an ST type connector, allowing the MADI output signal to be transmitted by fibre if preferred. Recommended fibre types are 62.5/125 µm or 50/125 µm, multimode. Transmission distances of at least 1000 m are achievable.
SDI Input | MADI Channels |
| |
SDI 1 | 1 to 16 |
SDI 2 | 17 to 32 |
SDI 3 | 33 to 48 |
SDI 4 | 49 to 64 |
| |
Redundant MADI connection
Using an SSL MADI Opti-Coaxunit the copper coaxial MADI signal can be converted to a parallel optical signal for a redundant optical connection (or vice versa for a redundant copper connection)
RS-422 Port
The rear panel includes an RS-422 port on a 9-pin female Dsub connector. This connector has no function at this time.
GPIO Port
A GPIO (General-Purpose Input-Output) port is available at the rear panel in the form of a 9-pin female Dsub connector. This has four inputs and four outputs, and allows the SDI-MADI’s four output SRCs (Sample Rate Converters) to be enabled from external control equipment by contact closure. Tallies confirming the SRC status are also available on this connector.
Pinout is as follows:
GPIO Port Pin | Function |
| |
1 | GPI 1 |
2 | GPI 2 |
3 | GPI 3 |
4 | GPI 4 |
5Ground
6Talley 1
7Talley 2
8Talley 3
9Talley 4
GPI Wiring
The GPI inputs are opto-isolated internally, and activate when the pin is connected to 0 V. (i.e. connect pins 1-4 to pin 5 to activate).
Vcc
Pin 1* 
Pin 5 
* Pins 24 are identical
Talley Wiring
The tally outputs are open-collector type, with transistors rated to 24 V. The tallies will typically be used to drive LEDs; connect the cathode of the LED to the tally output and the anode, via a suitable resistor, to an external DC voltage of not more than +24 V. The 0 V reference of the external DC voltage should be connected to pin 5.
Ext
LED PSU
* Pins 79 are identical
ETHERNET Port
The XLogic SDI-MADI includes a standard Ethernet port (an RJ45 socket). This connector has no function at this time.
