How do you say "Recall" to a telephone?

[David Segall]

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
<http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1>
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?

 

[Ken Taylor]

"David Segall" <david@nowhere.net> wrote in message
news:mc36p1h9nvcibk20b6ltk1v4ido1kq0u4h@4ax.com...

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?

Wouldn't it be easier just to send the number again?

Cheers.

Ken

 

[Nicholas Sherlock]

David Segall wrote:

Can I send tones to emulate "Recall"

Whoops, misread you the first time. Recall is dropping the line for some
small amount of time (<1 second) and picking it back up again as a
signal to the phone company. You cannot emulate it with tones.

Cheers,
Nicholas Sherlock

 

[Ken Taylor]

"rowan194" <googlegroups@sensation.net.au> wrote in message
news:1133726738.029271.191540@z14g2000cwz.googlegroups.com...

From memory it's 100ms in duration and it's also known as "hookflash"

You need to be able to release and grab the line, you cannot do it with
audio...

I think from memory that ATD@ is a hookflash command but then you're hoping
that the modem correctly implements it and that it suits the line that's
being used. It would be more reliable to dial again.

Cheers.

Ken

 

[Franc Zabkar]

On Sun, 04 Dec 2005 16:01:36 GMT, David Segall <david@nowhere.net> put
finger to keyboard and composed:

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book.

LOL. An acoustic coupler.

I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?

Why not use a modem and a built-in app? Windows 98, for example, has
an app called "dialer.exe". You use the dialer to make the call and
then hang up the modem after picking up your parallel connected
telephone handset.

If you prefer to write your own app, then send commands such as ...

AT DT nnnnnnnn;

or ...

AT DT !*37#;

In the case of my Rockwell modem, the "!" flashes the switch hook for
a period of time defined by S-register S29.

For example, AT S29=70 sets the hookflash duration to 700msec.

Listen for modem responses such as "BUSY", "NO DIALTONE", "VCON", etc.

The ATH and ATH1 commands cause the modem to go on-hook and off-hook,
respectively.

If you have a "hardware" modem, then you could probably automate the
dialing procedure using a simple DOS batch file.

-- Franc Zabkar

Please remove one 'i' from my address when replying by email.

 

[Jasen Betts]

On 2005-12-04, David Segall <david@nowhere.net> wrote:

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?

"recall" is another name for a hook-flash (a rapiid onhook-offhook)

that's done with a '!' in the dial-string if your modem supports it.

atdt !*37#

Bye.
Jasen

 

[Rod Speed]

Clifford Heath <no@spam.please.net> wrote

Jasen Betts wrote

"recall" is another name for a hook-flash (a rapiid onhook-offhook)

I believe there are two standards for the duration of the
hook-flash, and the Australian one is between 100-500ms.
The other system is under 100ms, which was all that was
supported on one old (non-approved) phone we bought.

Both were supported by Aust designed and manufactured T200s

I used to simply bump the hang-up button instead, until we replaced it with a
legal phone.

 

[Kwyjibo]

"Rod Speed" <rod_speed@yahoo.com> wrote in message
news:3vic8bF15vl2sU1@individual.net

Clifford Heath <no@spam.please.net> wrote
Jasen Betts wrote

"recall" is another name for a hook-flash (a rapiid onhook-offhook)

I believe there are two standards for the duration of the
hook-flash, and the Australian one is between 100-500ms.
The other system is under 100ms, which was all that was
supported on one old (non-approved) phone we bought.

Both were supported by Aust designed and manufactured T200s

Nope. It only did 100ms or 500ms, depending on the switch setting.
There was no option for a TLB of under 100ms.

--
Kwyj

 

[David Segall]

"Ken Taylor" <ken123@xtra.co.nz> wrote:

"David Segall" <david@nowhere.net> wrote in message
news:mc36p1h9nvcibk20b6ltk1v4ido1kq0u4h@4ax.com...
I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?

Wouldn't it be easier just to send the number again?
That would be fine but it does not seem to work. I have tried sending

the number followed by *37# in response to the engaged tone. I have
also tried some variants involving one second pauses but all I get is
the engaged tone. Is there some way of sending the number that you
believe will work?

 

[Kevin Martin]

David Segall wrote:

Wouldn't it be easier just to send the number again?

That would be fine but it does not seem to work. I have tried sending
the number followed by *37# in response to the engaged tone. I have
also tried some variants involving one second pauses but all I get is
the engaged tone. Is there some way of sending the number that you
believe will work?

If you are getting busy tone, then you *must* hang up. Dialling anything
else without hanging first is just pointless. Try it manually. The
Recall code (*37#) is only a command that indicates that something else
is to follow, it certainly is not the equivalent of hanging up & letting
the line reset.

Kevin Martin

 

[David Segall]

Kevin Martin <kevinrailway@optusnet.com.au> wrote:

David Segall wrote:



Wouldn't it be easier just to send the number again?

That would be fine but it does not seem to work. I have tried sending
the number followed by *37# in response to the engaged tone. I have
also tried some variants involving one second pauses but all I get is
the engaged tone. Is there some way of sending the number that you
believe will work?


If you are getting busy tone, then you *must* hang up. Dialling anything
else without hanging first is just pointless. Try it manually.
I think you are right but I was responding to a post that proposed

sending the number again. "Hanging up first" does not solve my problem
because sending the original number after hanging up, not
surprisingly, results in the engaged signal again.

The Recall code (*37#) is only a command that indicates that something else
is to follow, it certainly is not the equivalent of hanging up & letting
the line reset.
I don't understand this bit. *37# does not expect anything else to

follow. Trying it manually indicates that if it is preceded by Recall
(Flash) it results in the Call Back behaviour I am seeking.

Kevin Martin

 

[Rod Speed]

Kwyjibo <kwyjibo@RemoveThis.ozdebate.com> wrote

Rod Speed <rod_speed@yahoo.com> wrote
Clifford Heath <no@spam.please.net> wrote
Jasen Betts wrote

"recall" is another name for a hook-flash (a rapiid onhook-offhook)

I believe there are two standards for the duration of the
hook-flash, and the Australian one is between 100-500ms.
The other system is under 100ms, which was all that was
supported on one old (non-approved) phone we bought.

Both were supported by Aust designed and manufactured T200s

Nope. It only did 100ms or 500ms, depending on the switch setting.

That is what I meant.

There was no option for a TLB of under 100ms.

He was just misstating that.

 

[Jasen Betts]

["Followup-To:" header set to aus.electronics.]
On 2005-12-05, David Segall <david@nowhere.net> wrote:

I don't understand this bit. *37# does not expect anything else to
follow. Trying it manually indicates that if it is preceded by Recall
(Flash) it results in the Call Back behaviour I am seeking.

so when the busy tone is detected you need to flash the hook (send the
recall pulse) and then send the tones, to flash the hook all other
devices on that line must be on hook. or the CO will only see a click.

how are you controlling the phone line?

--

Bye.
Jasen

 

[David Segall]

Jasen Betts <jasen@free.net.nospam.nz> wrote:

On 2005-12-05, David Segall <david@nowhere.net> wrote:

I don't understand this bit. *37# does not expect anything else to
follow. Trying it manually indicates that if it is preceded by Recall
(Flash) it results in the Call Back behaviour I am seeking.


so when the busy tone is detected you need to flash the hook (send the
recall pulse) and then send the tones, to flash the hook all other
devices on that line must be on hook. or the CO will only see a click.

how are you controlling the phone line?
"Controlling" is a bit of an overstatement. Franc Zabkar remembered

the modems of our youth and recalled the technical term. So I will say
that I am using an acoustic coupler. Here's my original post-

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -
http://telstra-fixed.custhelp.com/cgi-bin/telstra_fixed.cfg/php/enduser/std_adp.php?p_faqid=1154&p_created=1111370527&p_sid=v_z-edWh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MyZwX3Byb2RzPTAmcF9jYXRzPSZwX3B2PSZwX2N2PSZwX3BhZ2U9MSZwX3NlYXJjaF90ZXh0PXJlY2FsbA**&p_li=&p_topview=1
say to press "Recall" then *37#. Can I send tones to emulate "Recall"
or is it some other change of state on the phone line? If the latter,
what is it?
Thanks to several posts I now understand what Recall (Flash) does at

the exchange. For the time being I have accepted that I cannot
acoustically couple a Recall/Flash but I still would liked to send the
appropriate sequence of tones after the Flash to enable automatic call
back. I have, so far, failed. The Flash is not the problem since
automatic call back works if I use the phone to key in the *37# and
press dial.

 

David Segall wrote:

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -

IMHO just output the DTMF code for the command

 

Sorry about oversimplistic response to first post. Lots of good sense here and I was way too shallow.

 

[Kwyjibo]

<nospam@ever.com.au> wrote in message news:43C9FC64.565CFA0@ever.com.au

David Segall wrote:

I am writing a program that outputs DTMF tones from my computer
speakers to dial telephone numbers in my address book. I decided to
add a button to do automatic call back if the number is engaged. The
instructions in the phone book which are also here -

IMHO just output the DTMF code for the command

There is no DTMF tone for a TLB.


--
Kwyj