PSN-L Email List Message
Subject: Re: My broken DataQ AD converter
From: "tchannel" tchannel@..............
Date: Sat, 31 Mar 2007 13:29:46 -0600
Well Chris, You did it again! I hope your head doesn't get too =
big.....But facts are facts. From way over there, in the UK?, you were =
able to help me fix this silly AD board, here in Boise Idaho, USA.......
I do believe you were correct at every turn....
1 I do think this is an older 194 8 bit board, from your physical =
description.
2 The resistor numbers on the surface mount components were 1003, and =
2003. Of course the two missing ones had no numbers. But there was a =
pattern as the resistors were in a row, something like =
1003,2003,1003,2003,1003,2003,xxxx,2003, so I figured the xxxx was the =
1003, 100K
3 The other missing resistor was near others which had the 2003, so I =
figured the xxxx would be a 200K, the way it is built I could not see =
where these resistors were in the circuit. I soldered in the two =
missing resistors, and it is now working!!!!!!!
4 I did go to AmaSeis .ini files but did not see any "Channel # listed" =
so maybe it is always going to be Channel 1.
and never Channel 2,3, or 4.
5 I do think you are correct about someone modifying the board to run =
as a +5v and a -0, as these two missing resistors just did not fail and =
fall off, they look like they were purposely popped off, small scratch =
marks in their place.
Again, Many Thanks, Ted
----- Original Message -----=20
From: ChrisAtUpw@..........
To: psn-l@.................
Sent: Saturday, March 31, 2007 12:00 PM
Subject: Re: My broken DataQ AD converter
In a message dated 2007/03/31, tchannel@.............. writes:
Hi All, Looking closely at the board I see two resistors which are =
"Open" "cracked"
Its a wonder it works at all, but some parts of it do work. Channel =
1, only puts out + voltage, just a small amount of -
I think that account for the AmaSeis trace showing only the top part =
of an earthquake.
Hi Ted,
The input resistors are two 200 K in series. The offset line is =
100 K to the centre point. If any of them are damaged, it should not be =
difficult to replace them. Alternatively, could you unsolder the =
resistors on CH4 and replace the ones on CH1? The resistor values are =
printed on them eg 2003.
I get about -0.59 V on the offset line and about 90 mV on the =
input. I suspect that this is because the ADC is not in operating mode. =
The offset line should be -5V for +/-10V input. Check the voltage on the =
offset line while the channel is switched on?
However Channel, 2,3,4 all seem to work showing both positive and =
negative movement "In DataQ Software Only", in this software Channel 1, =
only shows positive trace movement, and, no negative.
You could get this with failed resistors. Is the range 5V or =
10V? I suspect that the ADC may have been 'modified' for a single =
polarity 5V signal? Can the friend who gave it to you provide any =
information?=20
When I connected my Sensor to Channel 2,3 or 4 Using DataQ, I was =
thinking it would then work in AmaSeis, but it does not. It looks as if =
AmaSeis will not read any Channel except Channel 1. Even though in DataQ =
Channel 2,3,4 all seem to work fine. If I connect the sensor to Channel =
3, AmaSeis shows a trace, but the trace does not move in either =
direction if I stimulate the sensor. This is true for Channel, 2,3,4. =
Only Channel 1, moves the trace in AmaSeis.
I think you can change the com port, in AmaSeis, but is there =
anywhere you can or need to change for Channel selection?
In DataQ I closed all the Channels except Ch. 3 and saved before =
closing. So If I were just using DataQ software, I would be =
operational.
Amaseis normally uses CH1 only. However there are two setup =
files Amaseis.ini and AS1.ini. It may be possible to set a different =
channel by editing and then saving the file, but I am not sure. I know =
that you get your different sample rates this way. If you use a Dataq =
and Amaseis without editing the ini file, you just get 6 SPS.
This information is taken from an old 8 bit DI-194 board, which =
I suspect that you have.
Regards,
Well Chris, You did it again! I =
hope your=20
head doesn't get too big.....But facts are facts. From way over there, =
in the=20
UK?, you were able to help me fix this silly AD board, here in Boise =
Idaho,=20
USA.......
I do believe you were correct at every=20
turn....
1 I do think this is an older 194 =
8 bit=20
board, from your physical description.
2 The resistor numbers on the =
surface mount=20
components were 1003, and 2003. Of course the two missing ones had =
no=20
numbers. But there was a pattern as the resistors were in a row, =
something=20
like 1003,2003,1003,2003,1003,2003,xxxx,2003, so I figured the xxxx was =
the=20
1003, 100K
3 The other missing resistor was =
near others=20
which had the 2003, so I figured the xxxx would be a 200K, the way it is =
built I=20
could not see where these resistors were in the circuit. I =
soldered in the=20
two missing resistors, and it is now working!!!!!!!
4 I did go to AmaSeis .ini files =
but did not=20
see any "Channel # listed" so maybe it is always going to be =
Channel=20
1.
and never Channel 2,3, or =
4.
5 I do think you are correct =
about someone=20
modifying the board to run as a +5v and a -0, as these two missing =
resistors=20
just did not fail and fall off, they look like they were purposely =
popped off,=20
small scratch marks in their place.
Again, Many Thanks, Ted
----- Original Message -----
Sent: Saturday, March 31, 2007 =
12:00=20
PM
Subject: Re: My broken DataQ AD =
converter
In a=20
message dated 2007/03/31, tchannel@..............=20
writes:
Hi All, Looking closely at the board I see two resistors =
which=20
are "Open" "cracked"
Its a wonder it works at all, but some parts of it =
do work.=20
Channel 1, only puts out + voltage, just a small amount of =
-
I think that =
account for the=20
AmaSeis trace showing only the top part of an =
earthquake.
Hi=20
Ted,
The input resistors =
are two=20
200 K in series. The offset line is 100 K to the centre point. If any =
of them=20
are damaged, it should not be difficult to replace them. =
Alternatively, could=20
you unsolder the resistors on CH4 and replace the ones on CH1? =
The=20
resistor values are printed on them eg=20
2003.
I get about -0.59 V on =
the=20
offset line and about 90 mV on the input. I suspect that this is =
because the=20
ADC is not in operating mode. The offset line should be -5V for +/-10V =
input.=20
Check the voltage on the offset line while the channel is switched=20
on?
However Channel, 2,3,4 all seem to work showing both =
positive=20
and negative movement "In DataQ Software Only", in this software =
Channel 1,=20
only shows positive trace movement, and, no negative.
You=20
could get this with failed resistors. Is the range 5V or 10V? I =
suspect that=20
the ADC may have been 'modified' for a single polarity 5V signal? Can =
the=20
friend who gave it to you provide any information?
When I connected my Sensor to Channel 2,3 or 4 Using=20
DataQ, I was thinking it would then work in AmaSeis, but it =
does=20
not. It looks as if AmaSeis will not read any Channel except =
Channel=20
1. Even though in DataQ Channel 2,3,4 all seem to work fine. =
If I=20
connect the sensor to Channel 3, AmaSeis shows a trace, but =
the trace=20
does not move in either direction if I stimulate the sensor. =
This is=20
true for Channel, 2,3,4. Only Channel 1, moves the trace in=20
AmaSeis.
I think you can change the com port, in AmaSeis, =
but is there=20
anywhere you can or need to change for Channel =
selection?
In DataQ I =
closed all the=20
Channels except Ch. 3 and saved before closing. So If I were =
just=20
using DataQ software, I would be operational.
Amaseis =
normally uses=20
CH1 only. However there are two setup files Amaseis.ini and AS1.ini. =
It may be=20
possible to set a different channel by editing and then saving the =
file, but I=20
am not sure. I know that you get your different sample rates this way. =
If you=20
use a Dataq and Amaseis without editing the ini file, you just get 6=20
SPS.
This information is =
taken=20
from an old 8 bit DI-194 board, which I suspect that you=20
have.
=20
Regards,
Chris =
Chapman=20
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