Hayes Protocol for Morse

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Hayes Proto For Morse 1 Intro 2. Date fmt 3. Implementation In Morse Fig. 1: Implementation of the Hayes Protocol in Morse 3.1. Config Of Params In CU 3.2. AT Commands 3.3. S Registers 3.4. Return Codes 3.5. Principle of Data Transmission Switching on the Modem Making a Connection without the Autoanswer Function Fig. 2: Making a Connection Without the Autoanswer Function	Fig. 3: Making a connection with the autoanswer function Radio Modem Not Responding Fig. 4: Radio Modem Not Responding Switching to Command Mode Fig. 5: Switching to Command Mode Terminating a Connection Fig. 6: Terminating a Connection Maintenance Packets Fig. 7: Maintenance Packets 4. Configuration Parameters Hayes Parameters Meaning of Parameters


Hayes protocol for MORSE
Simulation of a telephone modem.



1. Introduction
The Hayes protocol simulates the use of the Hayes-compatible telephone
modem, and uses standard AT commands. Some AT commands have no sense in
the radio modem and are therefore ignored, although the radio modem does
returns an OK to them (e.g. ATWn, AT&Nn). It is used for substituting a
telephone line.

The Hayes protocol uses maintenance packets for finding out if one of the
stations has been forcibly disconnected. In the case of a loss of the
connection the protocol terminates the connection.

The Hayes protocol uses these signals of the RS-232C interface: Rx, Tx,
RTS, CTS, DTR, DSR and CD. The RI signal is not used. RTS and CTS signals
are used as a hand shake (if set up in the SPe menu).

The Hayes protocol is not suitable (due to large overheads) for short
transmissions, when transmitting small volumes of data, because at least
one exchange of overhead packets is required for making a connection.



2. Date Format
Controlling and setting up all values is carried out:

by the user using the terminal (using AT commands), examples:

AT it is 0x41 54 0D
or:   
AT it is 0x41 54 0D 0A
response:   
OK it is 0x0D 0A 4F 4B 0D 0A
more complex AT command:   
ATD1234 it is 0x41 54 44 31 32 33 34 0D


Characters in commands can be written in lower and upper case, decimal
numbers or 0x hex.

using service access – SETR (by directly setting S-registers)

See chapterSection 4,“Configuration Parameters”



3. Implementation in Morse
Implementation of the Hayes Protocol in Morse

	
Fig. 1: Implementation of the Hayes Protocol in Morse

	DTE – Data Terminal Equipment.



3.1. Configuration of parameters in the CU
The Hayes protocol is configured using AT command or by setting the
S-registers.



3.2. AT commands
The radio modem can be in two defined states –

OFF LINE – the modem is hung up

ON LINE – the modem is connected, and here we define two states –

command mode
data transmission


AT commands used in the radio modem –


AT command Action
+++ transition from ON LINE – transmission of data to the command mode,
connection not interrupted, return to ON LINE status – transmission of
date by ATO command
A/ repeats the previous command
AT? help screen
AT?1 help screen No.1
AT?S returns the S-register values
ATQ0 response to commands on
ATQ1 response to commands off
ATV0 numerical response to command set (e.g. 1), also S14, bit 0x04
ATV1 character response to command set (e.g. Connect)
ATE0 local echo off, also S14, bit 0x01
ATE1 local echo on
ATI,I0 returns own number (network address)
ATDn calls entered “n” address, after CONNECT switches to ON LINE –
data transmission
ATDn; calls entered “n” address, after CONNECT remains in command
mode, does not switch to ON LINE – data transmission (switches to it
after ATO or ATO0)
ATH,H0 cancels connection (before ATH it must switch from ON LINE –
transmission of date to command mode +++), switches to OFF LINE
ATO,O0 return from command mode to ON LINE – data transmission
ATA “manual” response to call (if S0=0)
AT&C0 signal CD in MR25 is still ON, i.e. S14 bit 0x2=1
AT&C1 signal CD in CU switches according to state of connection, i.e. S14
bit 0x2=0 (ON LINE CD=ON, OFF LINE CD=OFF)
AT&W,&W0 under development
ATZ termination of connection, renewal of protocol user profile FLASH
memory, reset of protocol
AT&F sets default parameters (S-registers) in Hayes protocol “Set
default configuration profile”
AT&D0 ignores DTR status, S14 bit 0x10=0
AT&D2 for DTR->OFF:, hangs up, command mode, automatic response off, i.e.
S14 bit 0x10=1
AT&V returns S-register values in RAM (active profile) and FLASH (stored
profile)
ATSn=y sets S-register n to value y
ATSn? Returns register value n
ATXn Selection of set of possible return codes (significant if S14
0x08=1, i.e.permitted response)




3.3. S-registers



S0 S0=0 is not picked up automatically, an ATA command must arrive
S0 > 0 the autoanswer function is switched on after the first RING tone
S2 Escape code character – ESC – special character, used for
switching from ON LINE to OFF LINE, default „+“ 2BH (043)
S3 Carriage return character – CARRIAGE RETURN, default ODH (013)
S4 Linefeed character – LINE FEED, default 0AH (010)
S5 Backspace character – BACKSPACE, default 08H (008)
S7 Connect timeout (sec.) – part of the time (added to the time defined
by registed S29) over which the modem waits for a response to a call for
making a connection. If by the time S7+S29 no response CONNECT arrives
from the called modem, the modem sends a NO ANSWER message to the
connected DTE
S10 Carrier loss hangup timeout (10 sec.) – time in tens of seconds
after which the connection is automatically terminated, if there is no
communication, e.g. due to a loss of the radio connection. If it is set to
0, the connection is not terminated automatically (it is configured on the
calling modem side)
S12 Escape code quard time (1/50 sec.) – time delay in tens of
milliseconds before and after the sequence of three ESC commands for
converting the modem from ON LINE – transmission of data to the command
mode
S14 Flags– command echo, resulting code S14
bit 0 1
0x10 AT&D0 AT&D2
0x08 ATQ0 ATQ1
0x04 ATV0 ATV1
0x02 AT&C1 AT&C0
0x01 ATE0 ATE1
S15 S15=n ~ ATXn Set of return codes.
S29 Dial delay (1/10 sec.) dial delay between RING and CONNECT sec/10
configured on the calling modem side)


There is no sense in setting up other registers in the radio modem.



3.4. Return Codes
There are 5 sets of return codes (X0, X1, X2, X3 and X4) in register S15 .
There settings are given in the table.

Return codes are only displayed if they are permitted, i.e. response to
commands – ATQ0 is on.

ATV0/ATV1 – numerical/character response


Return codes Setting
X0 X1 X2 X3 X4
0 OK x x x x x
1 CONNECT x x x x x
2 RING x x x x x
3 NO CARRIER x x x x x
4 ERROR x x x x x
5 CONNECT 1200  x x x x
6 NO DIALTONE   x  x
7 BUSY    x x
8 NO ANSWER    x x
10 CONNECT 2400  x x x x
13 CONNECT 9600  x x x x
18 CONNECT 4800  x x x x
20 CONNECT 7200  x x x x
21 CONNECT 12000  x x x x
25 CONNECT 14400  x x x x
50 CONNECT 19200  x x x x




3.5.-Principle-of-Data-Transmission



Switching on the modem
After connecting the supply voltage the radio modem is set to the command
mode and configuration parameters stored permanently in memory are
uploaded. In this state the modem accepts commands and communicates only
with the connected computer. The CD signal is not active. In this state
the required configuration can be set up.



Making a connection without the autoanswer function
We can make a call for a connection using command ATDn, where n is the
address of the called radio modem. If the called radio modem is prepared
for communication it sends RING information to its computer which means
that it has been called. After executing command ATA (if no autoanswer is
set) on the called computer the calling radio modem is informed about the
connection that has been made and sends CONNECT information to its
computer. ATA needs to be sent by time S29, otherwise the connection will
not be made. After sending command ATA the period in register S29 is
counted again (from the beginning irrespective of how much time has
elapsed), and after it has elapsed CONNECT information is sent.

Register S0=0 – without the autoanswer function. An ATA command is
necessary for making a connection.

	
	Fig. 2: Making a connection without the 
	autoanswer function


Making a connection with the autoanswer function
Register S0>0 – with the autoanswer function. The calling radio modem
accepts a connection automatically without the need to enter an ATA
command. A RING occurs only once, irrespective of how many “rings” are
set in register S0.

	
	Fig. 3: Making a connection with the 
	Making a connection with the autoanswer function
autoanswer function

The called radio modem is informed by a return message that confirmation
has been received and the called radio modem also sends CONNECT
information to its computer. CONNECT information is sent upon expiry of
the period set in register S29. At this moment the radio modem comes ON
LINE – data transmission, activates the CD signal and is capable of
communicating with its reciprocal radio modem.



Radio modem not responding
If the called radio modem does not respond within the time given by the sum
of registers S7+S29, the calling modem according to registers S7+S29
returns NO ANSWER information to the computer. This state also applies to
the situation where the modem does not respond and also to the situation
when DTE does not respond.

If the called radio modem has already made a connection with another radio
modem we receive a BUSY reply on calling for a connection.
Radio modem not responding

	
	Fig. 4: Radio modem not responding



Switching to command mode
In the state ON LINE – data transmission all characters that the computer
sends to the modem are transferred to the reciprocal radio modem. An
exception is a sequence of three ESCAPE characters, which switch the radio
modem from the ON LINE – data transmission state to the command mode
(command mode – communication with the mode commences by means of AT
commands without the need to interrupt the connection). Before and after
this sequence there must be at least the space set in register S12. If the
radio modem was switched to command mode, the connection was not
interrupted, and then back to the ON LINE – data transmission state it
is possible to get using command ATO Pokud byl radiový modem přepnut do
příkazového módu, nebylo spojení přerušeno a zpět do stavu ON LINE
– přenos dat je možné se dostat příkazem ATO.



Switching to command mode

	
	Fig. 5: Switching to command mode



Terminating a connection
A connection can be terminated either by setting signal DTR OFF (AT&D2) or
sending a command ATH, ATH0. If we want to terminate a connection using a
command it is first necessary to set the radio modem to the command mode.
In the command mode we can terminate a connection using command ATH or
ATH0. Termination of a connection on one radio modem is transmitted to a
second radio modem. A message about termination of the connection is sent
to the second radio modem and this radio modem sends NO CARRIER
information to the connected computer. Both radio modems switch to the OFF
LINE state. After termination of the connection it is possible to make a
connection with another radio modem.
	
	
	Fig. 6: Terminating a connection



Maintenance packets
If a radio connection is lost both protocols carry out termination of the
connection independently after the set timeout. Timeout for recognising a
loss of connection is set in register S10. If register S10=0 the
connection is not checked. For recognising a radio connection loss
maintenance packets are used. Maintenance packets are sent if no user
communication takes place and they are sent by both modems independently.
Maintenance packets are always sent at the end of time S10/3 from both
sides. If communication is interrupted a NO CARRIER command is sent to
both modems upon expiry of period S10. Both radio modems switch to the OFF
LINE state.



Maintenance packets

	
	Fig. 7: Maintenance packets
S registers S10 and S29 are configured on the calling modem side so that it
is possible to ensure a relationship to other parameters. These values are
sent in a BEL packet to the called modem.
Types of Hayes protocol packets


Meaning of packet Morse data packet (typ 0A)
HANG 0x01
BEL 0x02 + S10 + S29
Reserved 0x03
BUSY 0x04
HOLD 0x05
ACK 0x06




4. Configuration Parameters
The Hayes protocol can be configured –

using AT commands (see help AT?, AT?1, AT?S)

in the modem menu SPe0t it is possible to set up a default set of
S-registers using the command set de(f)ault , or some of the user sets of
S-registers using the appropriate command. Individual S-registers can also
be set up separately.

Register values in SETR are displayed in hexadecimal but are entered in
decimal.

This setting is stored either in FLASH memory using the (w)rite command, or
is activated using the (I)nit command. If these parameters are not
initialised the protocol will not work with them.



HAYES parameters:
set     de(f)ault,
best of: (g)alaxy,
(H)oneywell master
(h)oneywell slave
S registers:
01 
00 2B 0D 0A 08 00 0C 00 00 06 
00 32 00 04 04 00 00 00 00 00 
00 00 00 00 00 00 00 00 0A 00 
ATE0 AT&C1 ATV1 ATQ0 AT&D0 ATX4
(SXX=YY)

(a)ddress:00000000h  (c)mdmode:0001h  (s)tate:0000h  hang (r)eason:0000h
(m)ode:0000
(C)RLF timeout:0000ms
(D)irect DCD:0000
(q)uit


Meaning of parameters –

Pre-set S-registers –

Default parameters –

HAYES parameters:
set     de(f)ault

Pre-set S-registers for special applications –

best of: (g)alaxy,
(H)oneywell master
(h)oneywell slave
Register values in individual pre-settings –


Register default Honeywell master honeywell slave galaxy
"gS0 01 01 00 04
"gS2 2B 2B 2B 2B
"gS3 0D 0D 0D 0D
"gS4 0A 0A 0A 0A
"gS5 08 08 08 08
"gS7 0C 0C 0C 0C
"gS10 06 06 06 06
"gS12 32 32 32 32
"gS14 04 10 14 10
"gS15 04 00 04 04
"gS29 0A 00 00 32


S-registers

S registers:
01 
00 2B 0D 0A 08 00 0C 00 00 06 
00 32 00 04 04 00 00 00 00 00 
00 00 00 00 00 00 00 00 0A 00 
ATE0 AT&C1 ATV1 ATQ0 AT&D0 ATX4
(SXX=YY)

ATE0 AT&C1 ATV1 ATQ0 AT&D0 – distributed register S14

ATX4 – register S15

Status of connection (does not set up, just shows current status of
communication)

(a)ddress:00000000h  (c)mdmode:0000h  (s)tate:0000h  
hang (r)eason:0002h  (m)ode:0000

(a)ddress:00000000h – address of modem with which there is (was) a
connection

(c)mdmode:0000h

0 - line – ON LINE mode – data transmission

1 - command – command mode

(s)tate:0000h – state the modem is in

0 - off line – hung up

1 - on line – connected from local station

2 - rmt on line – connection was called up by the other side (see address)

3 - connecting

4 - rmt connecting – attempt to connect initialised by other side

5 - hanging up

hang (r)eason:0000h – reason for cancelling connection (0,1,2,3 and 7),
or not making connection (4,5 and 6)

0-init – initialisation of protocol

1-rmt – hung up from other side

2-loc – hung up locally (ATH)

3-carrier loss – after switching off radio modem

4-busy

5-ata wait – ATA wait time elapsed

6-dial – S07 time elapsed (connect timeout)

7-dtr – signal DTR OFF (locally)

(m)ode:0000 – special setting (default settings recommended)

(C)RLF timeout:0000ms – if a non-zero timeout is set packets are only
sent if CLRF arrives or if the set timeout elapses

(D)irect DCD:0000 – on setting the DCD signal do not wait for S29 (dial
delay) to elapse

(D)irect DCD:0001 – signal DCD is set up after ATDx (x = any character)

(D)irect DCD:000L – signal DCD is set up after ATDL (signal DCD is set up

after sending the set character for ATD)

AT	it is	0x41 54 0D
or:
AT	it is	0x41 54 0D 0A
response:
OK	it is	0x0D 0A 4F 4B 0D 0A
more complex AT command:
ATD1234	it is	0x41 54 44 31 32 33 34 0D

AT command	Action
+++	transition from ON LINE – transmission of data to the command mode, connection not interrupted, return to ON LINE status – transmission of date by ATO command
A/	repeats the previous command
AT?	help screen
AT?1	help screen No.1
AT?S	returns the S-register values
ATQ0	response to commands on
ATQ1	response to commands off
ATV0	numerical response to command set (e.g. 1), also S14, bit 0x04
ATV1	character response to command set (e.g. Connect)
ATE0	local echo off, also S14, bit 0x01
ATE1	local echo on
ATI,I0	returns own number (network address)
ATDn	calls entered “n” address, after CONNECT switches to ON LINE – data transmission
ATDn;	calls entered “n” address, after CONNECT remains in command mode, does not switch to ON LINE – data transmission (switches to it after ATO or ATO0)
ATH,H0	cancels connection (before ATH it must switch from ON LINE – transmission of date to command mode +++), switches to OFF LINE
ATO,O0	return from command mode to ON LINE – data transmission
ATA	“manual” response to call (if S0=0)
AT&C0	signal CD in MR25 is still ON, i.e. S14 bit 0x2=1
AT&C1	signal CD in CU switches according to state of connection, i.e. S14 bit 0x2=0 (ON LINE CD=ON, OFF LINE CD=OFF)
AT&W,&W0	under development
ATZ	termination of connection, renewal of protocol user profile FLASH memory, reset of protocol
AT&F	sets default parameters (S-registers) in Hayes protocol “Set default configuration profile”
AT&D0	ignores DTR status, S14 bit 0x10=0
AT&D2	for DTR->OFF:, hangs up, command mode, automatic response off, i.e. S14 bit 0x10=1
AT&V	returns S-register values in RAM (active profile) and FLASH (stored profile)
ATSn=y	sets S-register n to value y
ATSn?	Returns register value n
ATXn	Selection of set of possible return codes (significant if S14 0x08=1, i.e.permitted response)


S0	S0=0 is not picked up automatically, an ATA command must arrive
S0	S0 > 0 the autoanswer function is switched on after the first RING tone
S2	Escape code character – ESC – special character, used for switching from ON LINE to OFF LINE, default „+“ 2BH (043)
S3	Carriage return character – CARRIAGE RETURN, default ODH (013)
S4	Linefeed character – LINE FEED, default 0AH (010)
S5	Backspace character – BACKSPACE, default 08H (008)
S7	Connect timeout (sec.) – part of the time (added to the time defined by registed S29) over which the modem waits for a response to a call for making a connection. If by the time S7+S29 no response CONNECT arrives from the called modem, the modem sends a NO ANSWER message to the connected DTE
S10	Carrier loss hangup timeout (10 sec.) – time in tens of seconds after which the connection is automatically terminated, if there is no communication, e.g. due to a loss of the radio connection. If it is set to 0, the connection is not terminated automatically (it is configured on the calling modem side)
S12	Escape code quard time (1/50 sec.) – time delay in tens of milliseconds before and after the sequence of three ESC commands for converting the modem from ON LINE – transmission of data to the command mode
S14	Flags– command echo, resulting code S14
	bit	0	1
	0x10	AT&D0	AT&D2
	0x08	ATQ0	ATQ1
	0x04	ATV0	ATV1
	0x02	AT&C1	AT&C0
	0x01	ATE0	ATE1
S15	S15=n ~ ATXn Set of return codes.
S29	Dial delay (1/10 sec.) dial delay between RING and CONNECT sec/10 configured on the calling modem side)

Return codes		Setting
Return codes		X0	X1	X2	X3	X4
0	OK	x	x	x	x	x
1	CONNECT	x	x	x	x	x
2	RING	x	x	x	x	x
3	NO CARRIER	x	x	x	x	x
4	ERROR	x	x	x	x	x
5	CONNECT 1200		x	x	x	x
6	NO DIALTONE			x		x
7	BUSY				x	x
8	NO ANSWER				x	x
10	CONNECT 2400		x	x	x	x
13	CONNECT 9600		x	x	x	x
18	CONNECT 4800		x	x	x	x
20	CONNECT 7200		x	x	x	x
21	CONNECT 12000		x	x	x	x
25	CONNECT 14400		x	x	x	x
50	CONNECT 19200		x	x	x	x

Meaning of packet	Morse data packet (typ 0A)
HANG	0x01
BEL	0x02 + S10 + S29
Reserved	0x03
BUSY	0x04
HOLD	0x05
ACK	0x06

Register	default	Honeywell master	honeywell slave	galaxy
"gS0	01	01	00	04
"gS2	2B	2B	2B	2B
"gS3	0D	0D	0D	0D
"gS4	0A	0A	0A	0A
"gS5	08	08	08	08
"gS7	0C	0C	0C	0C
"gS10	06	06	06	06
"gS12	32	32	32	32
"gS14	04	10	14	10
"gS15	04	00	04	04
"gS29	0A	00	00	32