July 25, 1993

The complexity of modems today is such that great care must be taken in setting up the 'initialization string'. This string is what connects the modem to the outside world, and how it will react.

My intention is to take some of the frustration out of setting up a modem for optimal use. As many modems come merely with a single sheet on how to install it in your computer, this text will aid you in getting the most out of your communications package.

							Jim Dickson
							Mississauga, Ontario
			           			Internet RN1020@ROSE.COM


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MODEM COMMANDS

Command				Function

A	manually answer incoming call

A/	repeat last command executed. Do not precede A/ with AT or follow 		with ENTER.

AT	appear at the beginning of every command line

B_	B0 = CCITT V.22/V.22bis compatibility
	B1 = Bell 103/212A compatibility

D_	0 through 9
	# and *
	P (pulse dialing)
	R (include at end of Dial command line to call originate-only 	                  	   modem).
	T (touch-tone dialing)
	W (wait for second dial tone)
	@ (wait for one or more rings, followed by 5 seconds of silence.
	, (pause)
	! (flash)
	; (return to Command Mode after dialing)

DS=n	dials 1 of 4 telephone numbers (n) stored in the modem's 			nonvolatile memory

E_	E0 = commands are not echoed
	E1 = commands are echoed

+++	switch from Data Mode to Command Mode; pause 1 second before
 	typing; do not follow with carriage return (se Registers S2 and 		S12.

H_	H0 = modem is on-hook (hung up)
	H1 = modem is off-hook, line and auxiliary relay

I_	I0 = display product identification code
	I1 = factory test
	I2 = internal memory test

L_	L1 = low speaker volume
	L2 = medium speaker volume
	L3 = loud speaker volume

M_	M0 = internal speaker off
	M1 = internal speaker off until carrier detected
	M2 = internal speaker always on
	M3 = speaker on until carrier detected and off while dialing

O_	O0 = return to data mode
	O1 = modem does not send responses

Sr?	read value in register r (r = 0-27)

Sr=n	set register r to value n (r = 0-27; n = 0-255)

V_	V0 = single digit response
	V1 = word responses

X_	X0 = Hayes Smartmodem 300 compatibility
	X1 = include CONNECT 1200 and CONNECT 2400 responses
	X2 = include dial tone detection responses
	X3 = include busy signal detection responses
	X4 = include both dial tone and busy signal detection responses

Y_	Y0 = modem does not send or respond to break signals
	Y1 = modem sends break signal for 4 seconds before discontinuing

Z_ 	Z0 = retrieves active configuration profile from stored 	     	              configuration profile 0 and performs 2 sec. modem self test
	Z1 = retrieves active modem configuration profile from stores 			     configuration profile 1

&C_	&C0 = keep carrier detect signal always ON
	&C1 = turn on carrier detect signal when remote carrier signal is 	               present

&D_	&D0 = modem ignores the Data Terminal Ready signal
	&D1 = modem returns to command mode and asynchronous operation 		 	      following an ON to OFF DTR transition
	&D2 = modem hangs up, returns to the command mode, and prepares 		      for asynchronous operation following and ON to OFF DTR 		  	      transition
	&D3 = modem resets following an ON to OFF DTR transition

&F	restores the modem to the default operating characteristics

&G_	&G0 = guard tone disabled
	&G1 = 550 Hz guard tone
	&G2 = 1800 Hz guard tone

&J_	&J0 = modem will use an RJ11, RJ41S, or RJ45S telephone jack
	&J1 = modem will use an RJ12 or RJ13 telephone jack

&L_	&L0 = modem is set up for dialup operation
	&L1 = modem is set up for leased-line operation

&M_ 	&M0 = modem is configured for asynchronous operation
	&M1 = modem enters synchronous mode after dialing asynchronously
	&M2 = synchronous terminal support only
	&M3 = manually originating a synchronous call 	

&P_	&P0 = United States setting for off-hook(make) to on hook(break) 	               ratio
	&P1 = UK and Hong Kong setting for off-hook to on-hook ratio

&R_	&R0 = modem turns on its Clear To Send signal when it detects the 		      Request To Send signal from the attached computer or 			      terminal
	&R1 = modem ignores the Request To Send signal and turns on its 		      Clear To Send when ready to receive data synchronously

&S_	&S0 = DSR remains on at all times
	&S1 = DSR operates according to RS-232C specifications

&T_	&T0 = ends test in progress
	&T1 = performs local analog loopback test
	&T3 = performs local digital loopback test
	&T4 = modem achnowledges remote digital loopback test performed 		      by a remote modem
	&T5 = modem ignores a remote modem's request for a remote digital 		      loopback test
	&T6 = perform a remote digital loopback test
	&T7 = perform a remote digital loopback test and self test
	&T8 = perform a local analog loopback test and self test

&V	displays configuration profiles

&W_	&W0 = stores the modem's active configuration profile in stored 		      configuration profile 0
	&W1 = stores the modem's active configuration profile in stores 		      configuration profile 1

&X_	&X0 = modem provides synchronous clock on EIA pin 15
	&X1 = modem accepts an externally provided synchronous clock from 		      the carrier detect signal being received and provides the 		      clock on EIA pin 15

&Y_	&Y0 = designates configuration profile 0 to be the default 			      configuration profile. When modem is turned on or reset, 		               configuration profile 0 will be retieved as the active 		               configuration profile
	&Y1 = designayes configuration profile 1 to be the default 			      configuration profile. When modem is turned on or reset, 		               configuration profile 1 will be retrieved as the active 		               configuration profile

&Zn	stores up to 4 telephone numbers in the modem's non-volatile
 	memory. Use DS=n to dial a number


			S-REGISTERS

				Default
Register	  Range		Value			Function

S0	0-255 rings	1	rings to auto-answer calls

S1	0-255 rings	0	count number of incoming rings

S2	0-127     ASCII	43	escape character

S3	0-127     ASCII	13	carriage return character

S4	0-127     ASCII	10	line feed character

S5	0-32,127  ASCII	8	backspace character

S6	0-255 seconds	2	dial tone wait time

S7	1-255 seconds	30	wait time for remote carrier

S8	1-255		14	delay time between loss of remote 		   	  1/10 seconds		carrier and hangup

S9	1-255		6	carrier detect response time
	  1/10 seconds

S10	1-255		14	delay time between loss of remote 		   	  1/10 seconds		carrier and hangup

S11	50-255		95	duration and spacing of touch tones
	  milliseconds

S12	0-255		50	escape characters guard time
	  1/50 seconds

S13	undefined

S14	bitmapped		echo, response, dialing and 				register		originate/answer register

S15	undefined

S16	0, 1, 2, 4	0	modem tests

S17	undefined

S18	0-255 seconds	0	length of modem tests

S19	undefined

S20	undefined

S21	bit-mapped		jack, clear to send & data terminal
 	register		ready signals, and long space disconnect

S22	bit-mapped		speaker and response register
	register

S23	bit-mapped	7	remote digital loopback request, data 	register				rate, parity and guard tone register

S24	not used

S25	0-255 		5	data terminal ready delay
	 1/100 seconds

S26	0-255 seconds	1	request-to-send-to-clear to 1/100 						seconds send delay fpr half-duplex 						operation

S27	bit-mapped		async/sync operation and line register
	register


		MODEM RESPONSES

Word 		Number		     
Responses		Responses          
(V1 command)	(V0 command)			Meaning

OK		0		modem successfully executed a 							command.
				Modem has switched from data mode 						to command mode

CONNECT		1		data connection made with remote 						modem at any baud rate

RING		2		modem has detected an incoming 							ring. Modem will only answer when 						given the A command, or when S0 is 						greater than 0

NO CARRIER	3		remote carrier signal lost or not 						detected within the time specified 						by S7; modem returns to command 						mode.

ERROR		4		modem has found an error in your 						command line, and returns to 							command mode

CONNECT 1200	5		modem has made a data connection at 						1200 bps

NO DIALTONE	6		with the W command, waits up to W 						command time; modem begins dialing 						as soon as dial tone is detected.

				when blind dialing, modem waits the 						S6 register time, then dials, 							regardless of whenther dial tone is 						detected

BUSY		7		modem has detected a busy signal 						after dialing automatically

NO ANSWER	8		you sent the Wait for Quiet Answer 						(@) command and the modem did not 						detect 5 secons silence

CONNECT 2400	10		modem has made a data connection at 						2400 bps
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