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Operation
The frequency constant is calculated as (using C syntax):
MSW = 0x00ff & round (frequency * 8.192) >> 1
LSW = 0xFF00 & round (frequency * 8.192) >> 8
Therefore, to generate 1234 Hz followed by 567 Hz the frequency constants must first be calculated.
For 1234 Hz:
MSW = (0x00ff & round (1234 * 8.192) ) >> 1
= (0x00ff & round (10108.928) ) >> 1
= (0x00ff & 10109) >> 1
= (0x00ff & 0x277d) >> 1
= 0x7d >> 1
= 0x3e
MSW = '3', 'E' or (0x33), (0x45)
LSW
= (0xff00 & round (1234 * 8.192) ) >> 8
= (0xff00 & 0x277d) >> 8
= 0x2700 >> 8
= 0x27
LSW = '2', '7' or (0x32), (0x37)
For 567 Hz
MSW = (0x00ff & round (567 * 8.192) ) >> 1
= (0x00ff & 0x1225) >> 1
= 0x25 >> 1
= 0x12
MSW = '1', '2' or (0x31), (0x32)
LSW
= (0xff00 & round (567 * 8.192) ) >> 8
= (0x00ff & 0x1225) >> 8
= 0x12 >> 8
= 0x12
LSW = '1', '2' or (0x31), (0x32)
To generate the tone sequence, the following must occur:
PC to C200:
'^', <CR>
C200 to PC:
'0', '1', '8' (C200 Response)
PC to C200:
'4', '1', '3', 'E', '2', '7', '~' (Initiate transmission and generate 1234 Hz)
C200 to PC:
'~' (Acknowledge that tone is being generated)
<PC must time the duration for the tone.>
PC to C200:
'^', <CR>
C200 to PC:
'0', '1', '8' (C200 Response)
PC to C200:
'4', '1', '1', '2', '1', '2', '~' (Keep transmission and generate 567 Hz)
C200 to PC:
'~' (Acknowledge that tone is being generated)
<PC must time the duration for the tone.>
PC to C200:
'^', <CR>
C200 to PC:
'0', '1', '8' (C200 Response)
PC to C200:
'4', '0', '~' (Cease transmission)
C200 to PC:
'~' (Acknowledge transmission has ceased)
Model L3149B C200 Advanced Desk Set
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