7
C
ONTROLLING
EIA-232
S
IGNALING
This chapter contains information about configuring the EIA-232
1
signalling between your computer and modem:
■
Data Terminal Ready
■
Data Set Ready
■
Carrier Detect
Data Terminal
Ready
Your computer sends a Data Terminal Ready (DTR) signal to the Business
Modem when it is ready to send and receive data. The &Dn command
tells the modem how to respond to the DTR signal.
Example:
Sending
AT&D1
before connecting with another device,
dropping DTR will enter Command Mode.
1.The EIA-232 Standard was formerly known as RS-232 (RS stands for
Recommended Standard).
For your modem to
Command
Ignore the state of DTR and act as if DTR is always present. Use
this command with equipment that cannot provide DTR.
AT&D0
If issued
before connecting with another device
, enter online
Command Mode during a call by dropping DTR. Most
communications software packages have a method for
toggling DTR. Refer to your software’s manual for details.
AT&D1
Respond normally to the DTR signal.
The Business Modem will not accept commands until your
computer sends a DTR signal. The call will end when the DTR
signal is dropped.To change the DTR recognition time, set
S-Register 25. See Appendix A,
S-Registers
for more
information.
AT&D2
Business Modem hangs up and resets upon loss of DTR signal.
AT&D3
Содержание OfficeConnect 56K Business
Страница 1: ... http www 3com com 3Com OfficeConnect 56K Business Modem Command Reference Published January 1999 ...
Страница 14: ...4 ABOUT THIS GUIDE ...
Страница 32: ...1 18 CHAPTER 1 CONNECTING TO YOUR ISP ...
Страница 42: ...3 6 CHAPTER 3 MODES OF OPERATION ...
Страница 64: ...7 4 CHAPTER 7 CONTROLLING EIA 232 SIGNALING ...
Страница 72: ...8 8 CHAPTER 8 CONTROLLING DATA RATES ...
Страница 80: ...9 8 CHAPTER 9 ACCESSING AND CONFIGURING THE BUSINESS MODEM REMOTELY ...
Страница 96: ...11 6 CHAPTER 11 FLOW CONTROL ...
Страница 108: ...12 12 CHAPTER 12 HANDSHAKING ERROR CONTROL DATA COMPRESSION AND THROUGHPUT ...
Страница 112: ...13 4 CHAPTER 13 DISPLAYING QUERYING AND HELP SCREENS ...
Страница 124: ...14 12 CHAPTER 14 TESTING THE CONNECTION ...
Страница 132: ...15 8 CHAPTER 15 TROUBLESHOOTING ...
Страница 162: ...B 14 APPENDIX B ALPHABETIC COMMAND SUMMARY ...
Страница 168: ...C 6 APPENDIX C FLOW CONTROL TEMPLATE ...
Страница 210: ...14 GLOSSARY ...