AudioScience Iyo Dante Symetrix Protocol

This document describes a ConMon control protocol that uses a simple pseudo GPIO interface to manipulate control points on an AudioScience Dante Iyo. It also outlines how status returns work.

The control protocol is defined for a 32 input and 32 output Iyo Dante device. Devices that have fewer inputs and outputs use the same ConMon control layout, but ignore controls that do not apply.

The Dante Iyo devices do not support Preset Save and Restore, but any settings made are restored after a power cycle.

Throughout this document IYO is used to mean and Iyo Dante device with a Dante module installed.

ConMon Protocol

Header Structure

This section is reproduced here from Symetrix document ComMon_Control_Interface_V2.doc.

What we refer to below as the “header” is actually the first few bytes of the message body or payload in terms of Audinate’s terminology. It does not include the Dante “opaque” header. It consists of a 32-bit message type identifier field, 16-bit header version, 16-bit message length, and 32 bits of reserved data.

uint16 message_version;	// 0x0001 for the first AudioScience version
uint16 message_type;	// pseudo-GPIO command/response = 0x8000, asynchronous response = 0x8001
uint16 header_version;	// 0x0000 for now
uint16 byte_count;	// number of bytes in message, including this header
uint32 reserved;	// future expansion, set to zero
char data[];	        // payload data

For pseudo-GPIO messages, the payload data looks like this:

uint16 gpio_count;	// number of 32-bit GPIO mask/value pairs in this message
uint16 gpio_offset;	// offset into the total number of 32-bit GPIO words supported by this device
uint32 mask0;	        // mask of values that are “significant” in this packet (active high)
uint32 value0;	        // values of the bits that are set to 0x1 in the mask
uint32 mask1;	        // similar for words 1 through N
uint32 value1;
    …
uint32 maskN;
uint32 valueN;

Note	gpio_offset is typically 0 but can be set to a non-zero offset to address a subset of the complete address space.

Note	All fields are in network byte order. Hence macros such as ntohs() and ntohl() may be necessary.

The offset field provides a way to expand to more GPIO words than can fit into a single 500-byte packet. (Ultimo limits all packets to 500 bytes.) It is not anticipated that this will be needed, but is added to match the Dante GPIO command set. It could also be used to change just word 1, for example. This field is unused by the IYO.

An identical packet format is used for communication in both directions. When a ConMon Control interface wishes to change a parameter, it sends a message type 0x8000 with the appropriate mask bits set. The IYO responds with the complete status, with mask bits set for each parameter that is valid. For example, the bits for things such as presets would not be set, but most everything else (phantom, switch state, LED status, version, etc.) would be set. This creates a way for a ConMon Control interface to query the complete device state. It could send a command with mask with all zeros, and would receive the complete status in return.

Asynchronous responses can be sent from the IYO to a ConMon Control interface. The main use for these is switch changes. Asynchronous changes are indicated with message type 0x8001. The mask field will indicate what value was changed. (It may be possible to integrate both responses and asynchronous changes into a single 0x8000 message. But it seems like differentiating these will simplify things and is more consistent with the Audinate query/status message pair system.)

Word and bit definitions

Note	Direction is from the perspective of the IYO ConMon device.

Table 1. Word 0 bit definitions - Control
Bit	Usage	Direction
0	Asynchronous response enable	Input
1	Flash/Find Unit (turns off after ~8 seconds)	Input
2	Reserved
3	Reserved
4	Reserved
5	Reserved
6	Reserved
7	Reserved
8..15	Minor version number as 8-bit value	Output
16..23	Major version number as 8-bit value	Output
24..31	LED brightness (percent)	Input

Note	Valid LED brightness values are 25, 50, 75, 100 (percent)

Table 2. Word 1 bit definitions - Device Information
Bit	Usage	Direction
0-15	AudioScience Adapter Type	Output
16..23	Audio Input Channel Count	Output
24..31	Audio Output Channel Count	Output

Table 3. Word 2 bit definitions - Phantom Power
Bit	Usage	Direction
0	Phantom Power Channel 1	Input
1	Phantom Power Channel 2	Input
2	Phantom Power Channel 3	Input
3	Phantom Power Channel 4	Input
4	Phantom Power Channel 5	Input
5	Phantom Power Channel 6	Input
6	Phantom Power Channel 7	Input
7	Phantom Power Channel 8	Input
8	Phantom Power Channel 9	Input
9	Phantom Power Channel 10	Input
10	Phantom Power Channel 11	Input
11	Phantom Power Channel 12	Input
12	Phantom Power Channel 13	Input
13	Phantom Power Channel 14	Input
14	Phantom Power Channel 15	Input
15	Phantom Power Channel 16	Input
16	Phantom Power Channel 17	Input
17	Phantom Power Channel 18	Input
18	Phantom Power Channel 19	Input
19	Phantom Power Channel 20	Input
20	Phantom Power Channel 21	Input
21	Phantom Power Channel 22	Input
22	Phantom Power Channel 23	Input
23	Phantom Power Channel 24	Input
24	Phantom Power Channel 25	Input
25	Phantom Power Channel 26	Input
26	Phantom Power Channel 27	Input
26	Phantom Power Channel 28	Input
28	Phantom Power Channel 29	Input
29	Phantom Power Channel 30	Input
30	Phantom Power Channel 31	Input
31	Phantom Power Channel 32	Input

Table 4. Word 3 bit definitions - Input Mute
Bit	Usage	Direction
0	Input Mute Channel 1	Input
1	Input Mute Channel 2	Input
2	Input Mute Channel 3	Input
3	Input Mute Channel 4	Input
4	Input Mute Channel 5	Input
5	Input Mute Channel 6	Input
6	Input Mute Channel 7	Input
7	Input Mute Channel 8	Input
8	Input Mute Channel 9	Input
9	Input Mute Channel 10	Input
10	Input Mute Channel 11	Input
11	Input Mute Channel 12	Input
12	Input Mute Channel 13	Input
13	Input Mute Channel 14	Input
14	Input Mute Channel 15	Input
15	Input Mute Channel 16	Input
16	Input Mute Channel 17	Input
17	Input Mute Channel 18	Input
18	Input Mute Channel 19	Input
19	Input Mute Channel 20	Input
20	Input Mute Channel 21	Input
21	Input Mute Channel 22	Input
22	Input Mute Channel 23	Input
23	Input Mute Channel 24	Input
24	Input Mute Channel 25	Input
25	Input Mute Channel 26	Input
26	Input Mute Channel 27	Input
26	Input Mute Channel 28	Input
28	Input Mute Channel 29	Input
29	Input Mute Channel 30	Input
30	Input Mute Channel 31	Input
31	Input Mute Channel 32	Input

Table 5. Word 4 bit definitions - Input 1-4 Trim
Bit	Usage	Direction
0-7	Input 1 Trim (signed char) -60..+24dBu	Input
8-15	Input 2 Trim (signed char) -60..+24dBu	Input
16-23	Input 3 Trim (signed char) -60..+24dBu	Input
24-31	Input 4 Trim (signed char) -60..+24dBu	Input

Table 6. Word 5 bit definitions - Input 5-8 Trim
Bit	Usage	Direction
0-7	Input 5 Trim (signed char) -60..+24dBu	Input
8-15	Input 6 Trim (signed char) -60..+24dBu	Input
16-23	Input 7 Trim (signed char) -60..+24dBu	Input
24-31	Input 8 Trim (signed char) -60..+24dBu	Input

Table 7. Word 6 bit definitions - Input 9-12 Trim
Bit	Usage	Direction
0-7	Input 9 Trim (signed char) -60..+24dBu	Input
8-15	Input 10 Trim (signed char) -60..+24dBu	Input
16-23	Input 11 Trim (signed char) -60..+24dBu	Input
24-31	Input 12 Trim (signed char) -60..+24dBu	Input

Table 8. Word 7 bit definitions - Input 13-16 Trim
Bit	Usage	Direction
0-7	Input 13 Trim (signed char) -60..+24dBu	Input
8-15	Input 14 Trim (signed char) -60..+24dBu	Input
16-23	Input 15 Trim (signed char) -60..+24dBu	Input
24-31	Input 16 Trim (signed char) -60..+24dBu	Input

Table 9. Word 8 bit definitions - Input 17-20 Trim
Bit	Usage	Direction
0-7	Input 17 Trim (signed char) -60..+24dBu	Input
8-15	Input 18 Trim (signed char) -60..+24dBu	Input
16-23	Input 19 Trim (signed char) -60..+24dBu	Input
24-31	Input 20 Trim (signed char) -60..+24dBu	Input

Table 10. Word 9 bit definitions - Input 21-24 Trim
Bit	Usage	Direction
0-7	Input 21 Trim (signed char) -60..+24dBu	Input
8-15	Input 22 Trim (signed char) -60..+24dBu	Input
16-23	Input 23 Trim (signed char) -60..+24dBu	Input
24-31	Input 24 Trim (signed char) -60..+24dBu	Input

Table 11. Word 10 bit definitions - Input 25-28 Trim
Bit	Usage	Direction
0-7	Input 25 Trim (signed char) -60..+24dBu	Input
8-15	Input 26 Trim (signed char) -60..+24dBu	Input
16-23	Input 27 Trim (signed char) -60..+24dBu	Input
24-31	Input 28 Trim (signed char) -60..+24dBu	Input

Table 12. Word 11 bit definitions - Input 29-32 Trim
Bit	Usage	Direction
0-7	Input 29 Trim (signed char) -60..+24dBu	Input
8-15	Input 30 Trim (signed char) -60..+24dBu	Input
16-23	Input 31 Trim (signed char) -60..+24dBu	Input
24-31	Input 32 Trim (signed char) -60..+24dBu	Input

Table 13. Word 12 bit definitions - Output Mute
Bit	Usage	Direction
0	Output Mute Channel 1	Input
1	Output Mute Channel 2	Input
2	Output Mute Channel 3	Input
3	Output Mute Channel 4	Input
4	Output Mute Channel 5	Input
5	Output Mute Channel 6	Input
6	Output Mute Channel 7	Input
7	Output Mute Channel 8	Input
8	Output Mute Channel 9	Input
9	Output Mute Channel 10	Input
10	Output Mute Channel 11	Input
11	Output Mute Channel 12	Input
12	Output Mute Channel 13	Input
13	Output Mute Channel 14	Input
14	Output Mute Channel 15	Input
15	Output Mute Channel 16	Input
16	Output Mute Channel 17	Input
17	Output Mute Channel 18	Input
18	Output Mute Channel 19	Input
19	Output Mute Channel 20	Input
20	Output Mute Channel 21	Input
21	Output Mute Channel 22	Input
22	Output Mute Channel 23	Input
23	Output Mute Channel 24	Input
24	Output Mute Channel 25	Input
25	Output Mute Channel 26	Input
26	Output Mute Channel 27	Input
26	Output Mute Channel 28	Input
28	Output Mute Channel 29	Input
29	Output Mute Channel 30	Input
30	Output Mute Channel 31	Input
31	Output Mute Channel 32	Input

Table 14. Word 13 bit definitions - Output 1-4 Trim
Bit	Usage	Direction
0-7	Output 1 Trim (signed char) -10..+24dBu	Input
8-15	Output 2 Trim (signed char) -10..+24dBu	Input
16-23	Output 3 Trim (signed char) -10..+24dBu	Input
24-31	Output 4 Trim (signed char) -10..+24dBu	Input

Table 15. Word 14 bit definitions - Output 5-8 Trim
Bit	Usage	Direction
0-7	Output 5 Trim (signed char) -10..+24dBu	Input
8-15	Output 6 Trim (signed char) -10..+24dBu	Input
16-23	Output 7 Trim (signed char) -10..+24dBu	Input
24-31	Output 8 Trim (signed char) -10..+24dBu	Input

Table 16. Word 15 bit definitions - Input 9-12 Output
Bit	Usage	Direction
0-7	Input 9 Output (signed char) -10..+24dBu	Input
8-15	Input 10 Output (signed char) -10..+24dBu	Input
16-23	Input 11 Output (signed char) -10..+24dBu	Input
24-31	Input 12 Output (signed char) -10..+24dBu	Input

Table 17. Word 16 bit definitions - Input 13-16 Output
Bit	Usage	Direction
0-7	Input 13 Output (signed char) -10..+24dBu	Input
8-15	Input 14 Output (signed char) -10..+24dBu	Input
16-23	Input 15 Output (signed char) -10..+24dBu	Input
24-31	Input 16 Output (signed char) -10..+24dBu	Input

Table 18. Word 17 bit definitions - Output 17-20 Trim
Bit	Usage	Direction
0-7	Input 17 Output (signed char) -10..+24dBu	Input
8-15	Input 18 Output (signed char) -10..+24dBu	Input
16-23	Input 19 Output (signed char) -10..+24dBu	Input
24-31	Input 20 Output (signed char) -10..+24dBu	Input

Table 19. Word 18 bit definitions - Output 21-24 Trim
Bit	Usage	Direction
0-7	Output 21 Trim (signed char) -10..+24dBu	Input
8-15	Output 22 Trim (signed char) -10..+24dBu	Input
16-23	Output 23 Trim (signed char) -10..+24dBu	Input
24-31	Output 24 Trim (signed char) -10..+24dBu	Input

Table 20. Word 19 bit definitions - Output 25-28 Trim
Bit	Usage	Direction
0-7	Output 25 Trim (signed char) -10..+24dBu	Input
8-15	Output 26 Trim (signed char) -10..+24dBu	Input
16-23	Output 27 Trim (signed char) -10..+24dBu	Input
24-31	Output 28 Trim (signed char) -10..+24dBu	Input

Table 21. Word 20 bit definitions - Output 29-32 Trim
Bit	Usage	Direction
0-7	Output 29 Trim (signed char) -10..+24dBu	Input
8-15	Output 30 Trim (signed char) -10..+24dBu	Input
16-23	Output 31 Trim (signed char) -10..+24dBu	Input
24-31	Output 32 Trim (signed char) -10..+24dBu	Input

Total payload size is

21 x 4 x 2 = 168 bytes