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derSchweiz
Guest
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 Posted: Fri Aug 11, 2006 3:14 am Post subject: Caller ID shows garbage sometimes work sometimes doesn't wor |
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I have a US Robotics 56K Voice ISA Internal modem in a Windows XP Pro SP2
box. I have a Caller-ID application for it and when I receive incoming
calls, sometimes the caller ID shows up correctly, but most of the time it
doesn't.
So I decided to see what I get in Hyper Terminal and issued the
initialization string AT#CID=1 and I got OK returned. -Modem supports Caller
ID- and I call my number from a cell phone.
I get strange things like this:
Say the number should be: 6045559874
I will get something like 6145559874 or 6445559874 or worse: 6#%5)5587$
Sometimes I will just get RING RING RING displayed and no Caller ID Data
at all (this is all done during the same testing session)
What would be the most likely cause of this? Modem drivers, hardware, bad
cabling?
Any help would be appreciated.
Thanks |
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Franc Zabkar
Guest
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| Posted: Sat Aug 12, 2006 6:21 am Post subject: Re: Caller ID shows garbage sometimes work sometimes doesn't |
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On Thu, 10 Aug 2006 22:14:15 GMT, "derSchweiz" <keine@keine.de> put
finger to keyboard and composed:
| Quote: | I have a US Robotics 56K Voice ISA Internal modem in a Windows XP Pro SP2
box. I have a Caller-ID application for it and when I receive incoming
calls, sometimes the caller ID shows up correctly, but most of the time it
doesn't.
So I decided to see what I get in Hyper Terminal and issued the
initialization string AT#CID=1 and I got OK returned. -Modem supports Caller
ID- and I call my number from a cell phone.
I get strange things like this:
Say the number should be: 6045559874
I will get something like 6145559874 or 6445559874 or worse: 6#%5)5587$
Sometimes I will just get RING RING RING displayed and no Caller ID Data
at all (this is all done during the same testing session)
What would be the most likely cause of this? Modem drivers, hardware, bad
cabling?
Any help would be appreciated.
Thanks
|
Your ISA modem is probably a "hard" modem in which case it would have
no drivers. Looking at the data patterns, it appears that one or more
bits are being randomly flipped.
6#%5)5587$ 36 23 25 35 29 35 35 38 37 24
6045559874 36 30 34 35 35 35 39 38 37 34
I'd suggest that this is a line or cabling issue. It may help to
analyse a last call diagnostic report to determine if there are
impairments on your telephone line.
If there are no impairments, then I'd suggest that the impedance of
your modem to caller ID signals may be too high. In this case I
suspect that you may be able to improve your modem's detection
sensitivity by altering the value of the appropriate resistor or
capacitor.
I'm assuming that the functional diagram would look like the
following:
1uF ringer
RING capacitor
signal ||
DSP ---- optoisolator ----||----|
| || |
| |
|------ transformer --+--/ ----+-- phone line
| hook |
| switch |
| |
|--R--C--|
caller ID data path (FSK)
|
<--host side--> | <--line side-->
|
When the line is ringing, the optoisolator passes the RING info to the
DSP. Between the first and second rings, the caller ID data is shunted
around the open hook relay by the RC (?) elements. If R is too big, or
if the caller ID signal is too weak, then the signal appearing at the
transformer will be too low. Reducing the value of R may be a solution
in this case. I have no idea about the legal aspects, though.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email. |
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derSchweiz
Guest
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| Posted: Sun Aug 13, 2006 10:43 am Post subject: Re: Caller ID shows garbage sometimes work sometimes doesn't |
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Thanks for the reply, I do believe it is a cabling problem. I found out
there was some AC lines close to the phone lines and I moved them apart and
that seemed to help a bit. I will get rid of the old cables and replace it
with Cat 5e tommorow.
Also, one strange thing that I saw on the phone line junction box is that
the line coming into the building is 3 wires.
RED (+50 VDC)
YELLOW (+50 VDC)
GREEN (-50 VDC)
As far as I know there are only RING (+) and TIP (-), what could the extra
wire be for?
With a ohmmeter Positive lead to RED and Negative lead to YELLOW and setting
of 20M ohms, the impedence seems to oscillate from unlimited to zero.
"Franc Zabkar" <fzabkar@iinternode.on.net> schrieb im Newsbeitrag
news:grqqd2pj3dnsfji450up4t2no39d3jbscq@4ax.com...
| Quote: | On Thu, 10 Aug 2006 22:14:15 GMT, "derSchweiz" <keine@keine.de> put
finger to keyboard and composed:
I have a US Robotics 56K Voice ISA Internal modem in a Windows XP Pro SP2
box. I have a Caller-ID application for it and when I receive incoming
calls, sometimes the caller ID shows up correctly, but most of the time it
doesn't.
So I decided to see what I get in Hyper Terminal and issued the
initialization string AT#CID=1 and I got OK returned. -Modem supports
Caller
ID- and I call my number from a cell phone.
I get strange things like this:
Say the number should be: 6045559874
I will get something like 6145559874 or 6445559874 or worse: 6#%5)5587$
Sometimes I will just get RING RING RING displayed and no Caller ID
Data
at all (this is all done during the same testing session)
What would be the most likely cause of this? Modem drivers, hardware, bad
cabling?
Any help would be appreciated.
Thanks
Your ISA modem is probably a "hard" modem in which case it would have
no drivers. Looking at the data patterns, it appears that one or more
bits are being randomly flipped.
6#%5)5587$ 36 23 25 35 29 35 35 38 37 24
6045559874 36 30 34 35 35 35 39 38 37 34
I'd suggest that this is a line or cabling issue. It may help to
analyse a last call diagnostic report to determine if there are
impairments on your telephone line.
If there are no impairments, then I'd suggest that the impedance of
your modem to caller ID signals may be too high. In this case I
suspect that you may be able to improve your modem's detection
sensitivity by altering the value of the appropriate resistor or
capacitor.
I'm assuming that the functional diagram would look like the
following:
1uF ringer
RING capacitor
signal ||
DSP ---- optoisolator ----||----|
| || |
| |
|------ transformer --+--/ ----+-- phone line
| hook |
| switch |
| |
|--R--C--|
caller ID data path (FSK)
|
--host side--> | <--line side--
|
When the line is ringing, the optoisolator passes the RING info to the
DSP. Between the first and second rings, the caller ID data is shunted
around the open hook relay by the RC (?) elements. If R is too big, or
if the caller ID signal is too weak, then the signal appearing at the
transformer will be too low. Reducing the value of R may be a solution
in this case. I have no idea about the legal aspects, though.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email. |
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