Omron CQM1H-SCB41 Operation Manual page 420

Hayes Modem AT Command Protocol
Modem Settings
When this protocol is used, it is required that the modem connected to the Serial Communications Board be
initialized to the following conditions:
Command echo
Result code display format
Speed display, busy/dialling tone detection at connec-
tion
Error correction data compression display
MNP setting
MNP class setting
V.42 compression, Error correction
Flow control between terminal modems
ER signal control
Escape code
Note 1. It is recommended that, in addition to the above settings, the abort timer should be set so that com-
munications are cut off if a communications error happened due to incidents such as cable disconnec-
tion between the Serial Communications Board and modem. Set the abort timer to 10 minutes for the
modem initialization (specialized) (Sequence No. 560, 570, 580). Refer to modem's manual for further
information about abort timers.
2. The data format of the modem (baud rate, data length, parity, stop bit) is set by AT commands issued
from a device connected to the modem. Its settings should conform to communications conditions of
the device which issues AT commands. Therefore when communications are made between the mo-
dem and Serial Communications Board, it is required that communications conditions should be set
by issuing AT commands from the Serial Communications Board.
3. Modem settings become invalid if the power supply is turned off and must be set again. However, a
memory backup function can be used to protect settings so that even after the power supply to the
modem is turned off, it can communicate with the previous setting conditions.
For Initialize Modem (specialized), the modem initialization command is built in as message data. However, for
Initialize Modem (general-purpose), the command must be specified in PMCR.
Setting Example for Modem Initialization Command
• MD24FB10V Using Sequence #550 (OMRON)
The following command is set in the words specified by the second operand of PMCR.
ATE0V0X4\V2\N3%C0*C0\X1&M0S26=10
0018 0032
AT E0 V0 X4 \ V 2 \ N3 %C 0 * C 0 \ X 1 & M 0 S 2 6 = 1 0
Character string length of modem initialization command (bytes)
Code length of PMCR when it is used (words)
Note Turn ON pin 4 of DIP switches SW3 on for this Modem (ER signal always ON).
Operand 1 #x550 (x: Communications port)
Operand 2 First address for storing initialization command character string C
Operand 3 None
C+0 Number of words from address set for operand 2 to end of data
C+1 Number of bytes for send data (initialization command)
C+2 Send data (initialization command)
: (Fill data to left for odd numbers of bytes)
C+n
No
Numeric format
Baud rate display enabled, busy and dialling tone
detection enabled.
Error correction/data compression display enabled
Error correction provided (auto-reliable mode)
MNP class 4
Not enabled
Not enabled
Always ON
+
Appendix N
4 digits BCD
4 digits BCD
ASCII
405