Ricoh D072 Service Manual page 614

Address
Busy tone signal state time tolerance for all ranges, and number of cycles
required for detection (a setting of 4 cycles means that ON-OFF-ON or
OFF-ON-OFF must be detected twice).
Tolerance (±)
680533 Bit 1: 0, Bit 0: 0 = 75% Bits 2 and 3 must always be kept at 0.
Bit 1: 0, Bit 0: 0 = 50% Bits 2 and 3 must always be kept at 0.
Bit 1: 0, Bit 0: 0 = 25%
Bit 1: 0, Bit 0: 0 = 12.5%
Bits 7, 6, 5, 4 - number of cycles required for cadence detection
International dial tone frequency
680534
upper limit (high byte)
International dial tone frequency
680535
upper limit (low byte)
International dial tone frequency
680536
lower limit (high byte)
International dial tone frequency
680537
lower limit (low byte)
International dial tone detection
680538
time
International dial tone reset time
680539
(LOW)
International dial tone reset time
68053A
(HIGH)
International dial tone continuous
68053B
tone time
International dial tone permissible
68053C
drop time
SM Appendix
Function
If both addresses
Hz (BCD) contain FF(H), tone
detection is disabled.
If both addresses
Hz (BCD) contain FF(H), tone
detection is disabled.
If 680538 contains FF,
the machine pauses for
20 ms the pause time (68053D
/ 68053E).
Belgium: See Note 2.
7-75
NCU Parameters
D067/D068/D069/D072