Hayes Modem At Command Protocol - Omron CQM1H-SCB41 Operation Manual

Hayes Modem AT Command Protocol

The Hayes Modem AT Command Protocol is used to make various settings or control remotely a Hayes
modem connected to the Serial Communications Board via RS-232C cable.
Protocol Configuration
The configuration of the Hayes Modem AT Command Protocol is shown below.
Sequence Communications
No. sequence name
550 Initialize modem (gen-
eral-purpose)
560 Initialize modem (spe-
570 cialized)
580
561 Dial
571
581
552 Password
553 Data send/receive
(general purpose
sequence)
554 Escape
555 Hang up
562 Initialize and dial
572
582
590 Escape to hang up
1. Ladder Interface Settings
YES: User settings are required for the 2nd and 3rd operands of PMCR.
NO: Send word allocation:
Receive word allocation: Set the constant 0000 for the 2rd operand (S).
2. For details about dialling, refer to sequences 561, 571 and 581.
Appendix N
Function
Initializes the modem connected to the
Serial Communications Board. The initial-
ization command is set in the words speci-
fied for the second operand of PMCR.
Initializes certain OMRON Modems.
Dials from the modem connected to the
Serial Communications Board. AT com-
mands and telephone numbers are set set
in the words specified for the second oper-
and of PMCR. This sequence can be used
only for certain OMRON modems.
After the line is connected, the password
sent from the other exchange is verified to
confirm that the line is connected to the
desired exchange. The normal value of a
password is set in the words specified for
the second operand of PMCR.
Sends arbitrary data to the exchange which
the line is connected. Send data is set in the
words specified for the second operand of
PMCR. Receive data is stored in the words
specified for the third operand of PMCR.
Shifts the modem to escape mode (the con-
dition in which command input is available
during data communications). The escape
code is fixed to "+++"
After shifting to escape mode, the line is
disconnected.
Executes continuously from initialization to
dialling operations for certain OMRON
Modems.
Executes continuously from shifting to the
escape mode to hanging up.
Set a dummy word address for the 3rd operand (D).
Ladder interface
Send word Receive word
allocation allocation
Yes No
No No
Yes No
Yes No
Yes Yes
No No
No No
Yes* No
No No
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