Extron • System 4
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Switcher Series • User’s Manual
Appendix A • RS-232 Programmer’s Guide
A-9
Hex, Decimal and Binary Examples for Converting Range Values
1. The Audio range is C1h to FFh for -31dB to +31dB and 31dec = 1Fh.
To calculate the mid-range (zero dB) add 31d to the low number.
C1h = 1100 0001bin
= -31dec = low end of range
1Fh = 0001 1111bin
= 31dec = half of range
E0h = 1110 0000bin
= 00dec = mid-range (zero) value
To set Audio to +10dB, add 10d (0Ah) to the mid-range (zero) value.
E0h = 1110 0000bin
= 00dB
0Ah = 0000 1010bin
= 10dec
EAh = 1110 1010bin
= +10dB
2. The picture control range is 81h to FFh for -63 to +63 and 63dec = 3Fh.
To calculate the mid-range (zero setting) add 31dec to the low number.
81h = 1000 0001bin
= -63dec = low end of range
3Fh = 0011 1111bin
= 63dec = half of range
C0h = 1100 0000bin
= 00dec = mid-range value (zero)
To set a picture control to -10, add 53d (63d - 10d) to the low end.
81h = 1000 0001bin
= -63 = low end of range
0Ah = 0011 0101bin
= 53 = 63 - 10dec
B6h = 1011 0110bin
= -10 = new setting
_______ This is one example of how it can be done. You could also subtract 10d (0Ah)
from the mid-range value.
Select Input - CMD4 (34h)
CMD4 is for selecting video and audio input channels. The flexibility of this
command is that it allows for selection of audio and video from separate
channels (Breakaway mode) or from the same channel (Audio Follow).
By using a “no change” parameter it can be used to select either audio or video,
without changing the other. The command can also specify System 4
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only, or
System 4
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and the display device. The range of channel numbers is 1 thru 22.
Format: ESC, CMD4, Subcom4.1, Vid#, Aud#, EOT
Where: ESC, CMD4 =
1Bh, 34h
Subcom4.1
80h = System 4
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affected
81h = System 4
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and Projector affected
Vid#
80h = No changes
81h = Video input #1
82h = Video input #2
83h = Video input #3
etc.
96h = Video input #22 (highest number)
Aud#
80h = No changes
81h = Audio input #1
82h = Audio input #2
83h = Audio input #3
etc.
96h = Audio input #22 (highest number)
EOT = 04h = End of transmission
Example: Select Switcher Video input #17 and Audio input #3
1Bh, 34h, 80h, 91h, 83, 04h
Note: Input numbers are in hexadecimal (91h = 1001 0001bin = 145d).
Response: ESC, CMD4, ERC, EOT
