Set Startup Scene & Timeout Delay

It may be useful for the DMX engine to auto-load a stored scene immediately after a power cycle. Often a control system may take tens of seconds, or even several minutes, to restore its state after an unplanned outage. For this reason, the DMX Engine can load a pre-saved scene immediately after power is applied.





U1,5[cr] Load scene #1 five seconds after a power cycle

U0,0[cr] Change to zero startup scene. All DMX channels are zero until the connected equipment (Crestron, AMX, Control4, etc) sends commands:


  • U is a capital U

  • X is the pre-saved scene number, [0 60]. Leading zeros not required.

  • If X = 0, no scene will load and system will run normally. The default startup behavior is to set all

    channels to zero. If X is set to zero, T should be zero as well.

  • X is followed by a comma [,]

  • T is the approximate time, in seconds, the system will wait after startup to load the scene. DMX

    output will be live and the system will respond to commands during this period. If any regular serial command is received during this time, the startup scene will not be recalled. Value here is [0 255], leading zeroes not required.

  • [cr] is a carriage return, hex $0D or decimal 13.

  • U?[cr] queries the startup scene status, and an ASCII string is returned to the user.



  • Prior to defining a startup scene, the scene should be built and stored using the regular 'G', ‘F’ or ‘A’ commands, then stored with ‘S’. 

  • An uninitialized scene will probably / possibly default to ‘all channels on.’ This is because a raw-

    from-factory memory chip is loaded with ‘255’ or ‘0xFF’ as values. So be careful what you choose

    to load without first pre-programming.

  • The timing value ‘T’ is approximate and may vary by +/- 10% or so.