On Sun, 31 Mar 2019), in the Usenet newsgroup comp.dcom.modems, in article
<q7p08q$821$
1...@news.albasani.net>, bob prohaska wrote:
>The problem would be to get the modems to ignore the lack of
>dialtone and ringtone.
Found the manual for USR-1787 (56k Sportster dated 1997) - doesn't
appear to be supported.
Found _files_ (but not the CD) for USR-5637 (USB Hi-Speed modem
from 2012) now /usr/share/doc/5687/5637.ref_data which says:
Xn Sets result codes displayed. X4 This command enables tone
detection options used in the dialling process. As each function
is chosen, the modem's result codes are also affected. Therefore,
this command is frequently used to control the modem's responses.
The primary function of this command is to control call response
capabilities.
The default seems to be X4
Command Extended Dial Tone Busy Tone
Result Codes Detect Detect
X0 Disabled Disabled Disabled
X1 Enabled Disabled Disabled
X2 Enabled Enabled Disabled
X3 Enabled Disabled Enabled
X4 Enabled Enabled Enabled
X5, X6 Enabled Enabled Enabled
X7 Disabled Enabled Enabled
Option Description
Function Enabled Disabled
Ext Result Codes Displays basic result codes, connect messages
with data rate, and an indication of the modem's error correction
and data compression operations. Displays the basic result codes.
Dial Tone Detect Dials upon detection of a dial tone and
disconnects the call if the dial tone is not detected within 10
seconds. Dials a call regardless of whether the modem detects a
dial tone. Register S6 contains the dial delay.
Busy Tone Detect Monitors for busy tones. Ignores all busy tones.
Option Result Codes
Command Result Codes
X0 • OK • Ring • Error
• Connect • No Carrier
X1 • OK • Ring • Error
• Connect <Rate> • No Carrier
X2 • OK • Ring • Error
• Connect <Rate> • No Carrier • No dial tone
X3 • OK • Ring • Error
• Connect <Rate> • No Carrier • Busy
• Blacklisted
X4 • OK • Ring • Error
• Connect <Rate> • No Carrier • Busy
• Blacklisted • Delayed • No dial tone
• Call Waiting detected
X5, X6 • OK • Ring • Error
• Connect <Rate> • No Carrier • Busy
• Blacklisted • Delayed • No dial tone
• Call Waiting detected
X7 • OK • Ring • Error
• Connect • No Carrier
I suspect this was originally a Hayes command, as an old copy of
Scott Mueller's "Upgrading And Repairing PCs" (3rd edition from
1993) has near-identical information in a Modem Commands appendix.
Old guy