Omron CQM1H-SCB41 operation manual Escape Mode, Hang Up Command, Communication Errors

Hayes Modem AT Command Protocol Appendix N

Setting Example

When send data is THIS IS SAMPLE.

0009 0014 5448 4953 2049 5320

5341 4D50 4C45

T H I S I S S A M P L E

Character string length of send data sent to modem (bytes)

Code length of PMCR when it is used (words)

A maximum of 200 bytes (including the CR) can be received. When the received data is RETURN OK, the content stored in the receive words is as follows:

0006 5245 5455 524E 204F 4B00

R E T U R N O K

Length of received character string (words)

Note An error will occur is the reception data is not received within 90 seconds after the data is sent.

Escape Mode

Shifting to the escape mode can be made using sequence No. 554. No setting is necessary for this sequence.

Note The character string to shift the online mode to the escape mode (i.e., the escape code) is ‘+’ for modem settings.

Hang Up Command

The hang up command (to disconnect the line) can be executed using sequence No. 555. No setting is necessary for this sequence.

Communication Errors

Three result codes are monitored after an AT command is sent to the modem. When a result code is returned, it will be checked. If the code is not the normal result code (“OK”, “CONNECT 9600/REL4”, “CONNECT 2400/REL4”, in words), after a fixed time of waiting to send, the following retry processing will be repeated 2 times to send the AT command again and waiting for another result code.

The receive monitoring time and send wait time for each sequence are shown below.

Sequence	Sequence name	Receive monitoring time	Send wait time for retries
No.
#550	Initialize modem (general-purpose)	10 s	1 s
#560	Initialize modem (specialized)	10 s	1 s
#570
#580
#561	Dial	90 s	90 s
#571
#581
#552	Password	None	3 s
#553	Data send/receive (general-purpose)	90 s	None
#554	Escape	10 s	1.5 s (after first try)
#555	Hang up	10 s	1.5 s (after first try)
#562	Initialize and dial	90s	Initializing: 1 s
			Dialling: 90 s
#572
#582
#590	Escape and hang up	10 s	1.5 s (after first try)

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