Aphex Systems 1788a instruction manual Hardware Hook-up, Control Assertion

2.2.1 Hardware Hook-up

Anything from a single 1788A to a large constellation can be controlled by indirect MIDI through 1788A-R’s. Figure 2-5 suggests how this is done. The controller’s MIDI OUT is connected to the first 1788A-R’s MIDI IN. The next 1788A-R’s MIDI IN is connected to the preceding MIDI THRU, and so on.

2.2.2 Control Assertion

Depending on your needs, there are two control assertions available to MIDI:

1.Parametric control of any mic channel across the constellation.

2.Recall of one of the 60 presets that are stored in the 1788A-R’s memory.

In case 1, you will send one SysEx packet from the MIDI controller. The 1788A-R will then redirect commands across the LAN according to Net Number within its Bank. Additional 1788A-R’s can be cascaded by using MIDI Thru looping to control more banks. In the second case, the MIDI Preset Recall commands are shorter, containing only 2 bytes. The following figure illustrates the composition of the parametric and recall strings.

Fig. 2-6. Two Kinds of Remote Control Assertion

SysEx Start	Aphex MIDI I.D.	1788A-RMIDI Channel
		xx
F0	00 00 38

(00 to 0F)* Offset by -1 from 1788A-R Channel Number

(00-0F) Any Number Works.

(00 to 0F)* Offset by -1 from 1788A Net Number

See Command Table

Mic Channel (01-08)

See Command Table

*See hexadecimal conversion table.

OnlyPlaceholder 1788ANumberNet Command ChannelMic Value EndSysEx

SysEx Parametric

Control String

00 xx xx xx xx F7

MIDI Preset	Code	Number
Command		Preset
	Cx	xx

Range C0 to CF (C0 added to 1788A-R Channel Number -1)

Range 01 to 3C.

Hex Value of Preset Number (0-60).

The MIDI Preset Call omits the SysEx beginning and ending bytes. When a byte starting with “C” is seen by the 1788A-R, it recognizes the preset command. The MIDI channel I.D. is inferred from the first byte value Cx where x is the channel number 0h to Fh (1 to 16).

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