MIDI Show Control Messages

This section of the Help provides details on the SCS support for MIDI Show Control (MSC) messages. MSC message bytes are principally defined using their hexadecimal values, such as 7FH (7F hexadecimal = 127 decimal).

Device Id: For MSC messages you need to select the Device Id that identifies SCS in the MSC network. In an MSC environment each device is uniquely identified by assigning a Device Id, although you can have more than one device sharing the same Device Id. Select an Device Id in the range 00H to 7EH. For an individual device you should select a Device Id in the range 00H to 6FH, as Device Id's in the range 70H to 7EH are allocated to Group Id's. SCS accepts MSC messages that have a Device Id that matches the MSC Device Id and also MSC messages that have a Device Id of 7FH ("All Call").

MSC Command Format: This should normally be left at the default setting of 10H, which is the Sound (General Category) format. Sometimes, however, you may want to link SCS to a controller that sends MSC messages using a different format. For example, the ETC Express lighting desk sends MSC commands using format 01H - Lighting (General Category) as it is intended for controlling other lighting desks. If, in fact, you are using it to control SCS cues then you need to set this Command Format to 01H. If you can select a command format on the controller then you should select 10H for sound cues.

'Go' Button Macro #: This identifies the Fire command's macro number that activates the SCS 'Go' button. The default setting is macro 0, but the device you are using to send MSC commands may not be able to send 0 - some devices only send macro numbers 1 to 127. If you are using the MSC Fire command for activating SCS cues, select the required macro number to be used for the 'Go' button. Note that the number you choose should preferably not be a number you use as a MIDI cue number as this could cause confusion to operators.

SysEx message to run a cue

The format of a Show Control message is as follows, where fixed value bytes are shown in hexadecimal:

F0 7F <Device Id> 02 <Command Format> <Command> <Data> F7

For SCS the required message format is as shown below:

Byte type

Value
(Hex)

Description

Start byte

F0

Start of SysEx message.

Start of message

7F

 

Device ID

?

The 'Device ID' that represents SCS, or 7F for "all-call" if a system-wide broadcast.

SysEx message

02

Denotes a MIDI Show Control message.

Command format

10

SCS by default expects a command format of hex 10 - Sound (General Category), but any other valid command format can be set. SCS also responds to 7F - All-Types.

Command

?

Commands currently recognized by SCS are:
   01 - GO
   02 - STOP
   07 - FIRE

See MSC Commands below for details.

Data: Cue number or Macro number

?

Cue number is used for GO and STOP commands. It may be omitted as explained under MSC Commands below, but if it is entered then the format of an MSC cue number is:
   <Q_number> 00 <Q_list> 00 <Q_path>

SCS only uses the Q_number component. The 00 delimiters and other components are optional - SCS reads the Q_number up to the first 00 delimiter or up to the F7 SysEx stop byte, whichever comes first.

Q_number, Q_list and Q_path are expressed as ASCII numbers 0-9 (encoded as 30H-39H) with the ASCII decimal point character (2EH) used to delineate subsections. SCS maps the Q_number to an SCS MIDI Cue #.

For example, cue 235.6 would be represented by the hex data:
   32 33 35 2E 36

Macro number is used for FIRE commands and is used as explained under MSC Commands below. The macro number is a 7-bit number (maximum value 127 decimal) occupying only one byte.

For example, macro number 110 (mapping to MIDI Cue #110) would be represented by the hex data:
   6E

Stop byte

F7

End of SysEx message.

MSC Commands

The MSC commands currently recognized by SCS are as follows:

  GO  

If no cue number is supplied, the Go button is activated, starting the next manually started cue in the cue list. Note that in SCS this could be any type of cue, ie a sound file cue, a stop cue, a level change cue, or a cue containing any combination of cue types.

If a cue number is supplied, the SCS cue whose MIDI Cue Number matches the Q_number is activated. If no such cue is found the command is ignored.

  STOP  

If no cue number is supplied, all currently running cues are stopped.

If a cue number is supplied, the SCS cue whose MIDI Cue Number matches the Q_number is stopped. If no such cue is found the command is ignored.

The MSC STOP command stops cues immediately, ignoring fade out settings. If you require a cue to be faded out then as well as specifying a fade-out time for the cue you need to create a Stop Cue for that cue, and use the MSC GO command to activate the Stop Cue instead of using the MSC STOP command.

  FIRE  

SCS does not have a macro facility but MSC Fire Macro messages can be used to activate SCS cues as follows:

If the macro number matches the 'Go Macro', the Go button is activated, starting the next manually started cue in the cue list.

If the macro number does not match the 'Go Macro', the SCS cue whose MIDI Cue Number matches the macro number is activated. If no such cue is found the command is ignored.

Back to Cue Control Devices - MIDI