KRAMER: SIMPLE CREATIVE TECHNOLOGY
VP-23 Communication Protocol
10
Table 6: Instruction Codes
INSTRUCTION
DEFINITION FOR SPECIFIC INSTRUCTION
NOTE
# DESCRIPTION
INPUT
OUTPUT
0
RESET MACHINE
0
0
1
1
SWITCH GROUPS
1-4 Set equal to video and audio
inputs to be switched for the
relative group
1-3 Set equal to group which
output to be switched
2
2
SWITCH AUDIO OUTPUTS
1-4 * Set equal to audio output to
be switched to Master Audio out.
1
2
5
REQUEST GROUP STATUS
0
1-3 Set equal to the group of
which status is required.
3
6
REQUEST STATUS OF
MASTER AUDIO OUTPUT
0
1
3
16 ERROR/BUSY
Don’t care
Don’t care
4
18 RESET MACHINE
0
0
1
57 SET AUTO SAVE
1 – autosave
2 – no save
Don’t care
5
61 IDENTIFY MACHINE
1 or 2 – machine name
3 or 4 – program version
Don’t care
6
* #4 – for microphone.
NOTES
on the above table:
NOTE 1
- When the master switcher is reset, (e.g. when it is turned on), the reset code is sent to the PC. If this code is sent to
the switchers, it will reset according to the present power-down settings.
NOTE 2
- These are bi-directional definitions. That is, if the switcher receives the code, it will perform the instruction; and if
the instruction is performed (due to a keystroke operation on the front panel), then these codes are sent. For example, if:
0000 0001 Instruction “Switch Groups”
1000 0010 Input #2
1000 0001 in composite video group
1000 0001 Machine #1 (master)
Was sent from the PC, then the switcher (machine #1) will switch input 2 in composite video group to its output. If the user
switched input 4 in the VGA group via the front panel keypad, then the switcher will send:
0100 0001
1000 0100
1000 0011
1000 0001 to the PC.
When the PC sends instruction #1 or #2 to the switcher, then, if the instruction is valid, the switcher replies by sending the
same four bytes to the PC that were sent (except for the first byte, where the DESTINATION bit is set high).
NOTE 3
– To reply to a “REQUEST” instruction is as follows: the same instruction and input codes as were sent are
returned, and the OUTPUT is assigned to the value of the requested parameter. The reply to the instruction #5 (what is the
status of the VGA group?):
0000 0101
1000 0000
1000 0011
1000 0001
Would be:
0100 0101
1000 0000
1000 0100
1000 0001
NOTE 4
– An error code is returned to the PC if an invalid code was sent to the switcher (for example, when trying to switch
an input or a group which is greater than the highest one defined). This code is also returned to the PC if an RS-232
instruction is sent while the machine is being programmed via the front panel. Reception of this code by the switcher will not
be valid.
NOTE 5
– Under normal conditions, the machine’s present status is saved each time a change is made. The power-down save
(the auto save) may be disabled using this code. Note that each time that the machine is turned ON, the auto save function is
automatically set.