



                ͻ
                 Release notes for rom version 6.12 
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             Firmware 6.12 release note      04-26-1994
                   ------------------------------

New Feature:

Modem

1. ZyCellular mode added

ZyXEL U-1496 Series modems are equipped with a special cellular communication 
mode which enables the modem to provide reliable high speed data transmissions 
over cellular phone links
          
In addition to normal modem, fax and voice operation modes, the following
cellular modes are offered in ZyXEL's U-1496 series modems:
          
Mode         Speed
          
Multi-Auto:  ZyX modes V.32bis/V.32/V.22bis/G3 FAX/Cellular Modes
CELL 14400:  14400/12000/9600/7200/4800 (AT&N42)
CELL 12000:  12000/9600/7200/4800 (AT&N43)
CELL 9600:   9600/7200/4800 AT&N44)
CELL 7200:   7200/4800 (AT&N45)
CELL 4800:   4800 (AT&N46)
          
CELL 14400 will connect with another modem using cellular mode at a speed
of up to 14400bps.  It will also connect with another V.32bis/V.32 modem.
The actual speed depends on the line condition. The modem will automatically
fall-back or fall-forward within its speed range. CELL 12000, CELL 9600,
CELL 7200 and CELL 4800 limit the maximum speed to 12000bps, 9600bps, 7200bps
and 4800bps, respectively.
          
In Multi-Auto mode a ZyXEL modem will automatically and dynamically select
the best speed and mode in which to operate. Selecting one of the above
cellular modes manually will limit the maximum speed at which the modem will
operate.

The ZyCellular Option is recommended when using cellular links for modem
connection. It can also be used on other poor line conditions such as a
line with frequent large impulse noises.  ZyCellular mode is more noise
resistant, impairment resistant, and error resistant.
          
It is simple to use the ZyCellular modems. Everything is determined
automatically by the modem.  The user needs only to set S-register S49
bit 7 to leave the modem on cellular mode. S49 bit 7 tells the modem
where it is installed.  If S49.7=0, the modem is installed in an office
connected to a normal telephone line.  If S49.7=1, it means the modem is
a mobile unit connected to a cellular phone.  When a ZyCellular modem
calls or answers another modem, it will indicate its cellular capability
and whether it is using a cellular phone.  If both sides have the ZyCellular
capability and at least one side is using a cellular phone, the connection
will automatically be a cellular mode connection.  If one side is a
non-cellular modem the connection will automatically be a standard mode.
          
If manual transmit power setting is desired, set S43.2=1 to disable auto
transmit power adjustment and use S49 bit 0-3 to set transmit power at -9
to -24 dBm.
          
If cellular mode connection is never desired, set S43.3=1 to disable the
cellular mode connection.  The default is enabled (S43.3=0).
          
You are also able to send and receive faxes on cellular links by just
setting S49.7=1 on the ZyCellular modem that is installed on the cellular
site.  Now your modem can send and receive faxes from fax machines and other
fax modems.

2. Support 100 dial digits on one dial string.

3. Bit s48.3 is used to reverse V.23 channel speed.

             Originate speed (send/receive)  Answer speed (send/receive)
   s48.3=0                    75/1200                      1200/75
   s48.3=1                    1200/75                      75/1200

4. Add ATO1 command, this command can force modem to request a retrain.

5. Set s48.4=1 and &D1, DTR ON will make the modem dial the default number
   and DTR OFF will make the modem hangup and reset profile 0. When the modem
   is idle -wait for command- it will not dial a number when the DTR signal
   from ON to OFF.

6. In EG+, no more blacklist but the modem delays 30 seconds between every
   call. Press D/V button on EG+ or "MENU" key on SG+ will skip the delay
   and dial immediately.

7. Set s25 to define DTR delay timing. s25 specifies the minimum time that
   DTR signal must be off to be recognized. Each units represents 10 ms.
   At least 4 ms for s25=0.


FAX

1. Class 2.0 Fax command is available on this version.

2. Add new command for class 2 .
    2.1:+FMINSP= Minimum phase C speed parameter (0 to 5).
        0:2400bps       1:4800bps       2:7200bps
        3:9600bps       4:12000bps      5:14400bps
    2.2:+FCQ= Copy quality check capability parameter (0 to 2).
        0:No copy quality check capability.
        1:Only check 1D phase C data.
        2:Check both 1D & 2D phase C data.
    2.3:+FK  orderly fax abort command.

3. Report Detailed HangUp code information for both Class 2 and Class 2.0.

4. Support T.4 1D/2D decompression, error line report and correction.
   Correction method for 1D: if the number of consecutive error lines are
   less than 4 lines the error line is substituted by the previous good line,
   otherwise the bad line is deleted. For 2D the error line is simply deleted.


VOICE

1. AT+VDD, This command sets the duration of DTMF tone detection. The unit is
   5 msec, default value is 6 (30msec). The modem reports DTMF event when it
   detects a continuous tone for this period.
             
2. AT+VDH, This command sets the threshold of the DTMF tone detection. The
   default value is 16. Decreasing the value makes the modem more sensitive.
   The range of VDH is 0-31.

3. The 2 and 3-bit ADPCM format is changed. It is necessary to add the leakage
   coefficient for every sample. Please refer to the C code program VCNVT.C
   and 610TO612.C for detail information. It is recommended to re-record your
   greeting message because the new leakage will give better voice quality.

4. AT+VGT, This command sets the playing volume of voice. The default value
   is 192, a higher value makes the voice louder. The range of VGT is 0-255.



Improvement:

Modem

1. Endless retrain on S48.1=1 (data mode only) is fixed.

2. Performance on V.26bis dial-up line half-duplex mode is improved.

3. In security call back mode, the DSR ans DCD will turn on only after call
   back has established.

4. In ATI2 response, ">100M" error message fixed.

5. Set s43.7=1 to fix DCE connection speed. Modem will disconnect the line
   condition does not permit the highest speed set by AT&N command.

6. In EG+ model, Flash "!" function is modified to be the same as E+.

Voice

1. "AT+VLS=16" command used to getresponse of "OK", it is corrected to "VCON".

2. Sending the "ATH" command in voice mode and offhook state used to hang
   the modem, bug fixed.

3. Sending "AT&F" following the command "AT+FCLASS=8" used to gets "NO CARRIER"
   , it is corrected to "OK".




		     Firmware 6.13 release note      07-19-1994
		   ------------------------------


New feature:

Voice


1. Add a new 3-bit ADPCM voice compression scheme, use AT+VSM=30 to select
   this mode. In this new format, every 5 samples of compressed data is
   packed into 2 bytes, the extra bit is set to 1 for resync.

	byte 1 :                    byte 2 :                  
		  1 A A A B B B C             C C D D D E E E 
							  

	1 : resync bit.
	A A A : first  sample
	B B B : second sample
	C C C : third  sample
	D D D : forth  sample
	E E E : fifth  sample
		
2. Add a new 4-bit ADPCM voice compression scheme, use AT+VSM=4 to select
   this mode. Two samples of compressed data is packed into 1 byte.
   It is necessary to increase the DTE speed to 57600 bps to use this
   compression scheme.

				  
		  A A A A B B B B 
				  

	A A A A : first  sample
	B B B B : second sample

3. Accept hardware flow control for voice data flow, use the command
   "AT+FLO=2" to enable the hardware flow control. (default value is
   "AT+FLO=1").


Improvement:

FAX

1. Improved 2-D high resolution graphic quality on E model.

2. Fax receiving speed is now command configurable on class 2 and
   class 2.0.




Modem

1. High DTE speed AT auto-baud detection problem on E model fixed

2. Ring volume control (ATNn) bug fixed

3. V.23 answer tone detection bug fixed.

4. V.26bis performance improved

5. V42 block resent count will have a wrong count when remote modem is busy,
   this bug is corrected.

6. Modem automatically disables terminal aborting if async leased line is
   set.

7. Modem can now accept V.25bis async command in sync-data (&M1) mode.

8. Set bit 7 of S52 to select space or mark as the first signal of the
   V.23 handshaking sequence.

9. The bug of modem disconnecting the line after second ATO1 command
   is fixed.

10. ATA will not cause "ERROR" response now if modem is already off hooked on
    EG+ model.

11. Will detect V22bis carrier longer to recognize it as a carrier presence
    to improve compatibility.

12. Hook flash time can be adjusted by setting S56, unit value is 10 ms.

13. Hardware reset (press D/V button on E, E+ or ENTER key on S+ while
    powering on) will only reset profile 0 and 1 but profile 2 and 3
    will not be affected.



