W3FPR: RE: [Elecraft] KIO2 sends out to pc but doesn't take commands from pc

[james1787 at aol.com]

Gary,

I took some measurements:

You mentioned when the K2 is not sending or receiving data that U1 pin 
11 and pin 12 should both be 5 volts. Pin 12 is 5 volts, but Pin 11 is 
0 volts. I also verified that U6 Pin 25 is 5 volts and U6 Pin 26 is 0 
volts. What could cause U6 Pin 26 to be 0 volts?

U1 Pin 5 is -10 volts, which is within the range you specified.

I verified the serial cable is built exactly to the manual's 
instructions. I verified that nothing is crossed by popping off the 
covers on each end and plugging the male/female into eachother. All 
colors lined up. I verified continuity with all pins.

I tried changing between U6 - 25 and U8-4 for the side tone source in 
the menu back and forth several times with no change in the output 
voltage of that U6 Pin 26. If that pin is supposed to be 5v and it's 
not, that seems to be raising a red flag, correct?

Where should I go from here?

Thanks & 73,

James Kern KB2FCV

-----Original Message-----
From: support at elecraft.com
To: w3fpr at arrl.net; james1787 at aol.com; elecraft at mailman.qth.net
Cc: csinfo at elecraft.com
Sent: Fri, 27 Oct 2006 8:15 PM
Subject: W3FPR: RE: [Elecraft] KIO2 sends out to pc but doesn't take 
commands from pc

Anything less than 10 ohms means the RFC is OK.


Here are more KIO2 troubleshooting tips:


BEGIN:


Here are some things about testing the KIO2: (also applies to the KPA100
RS232 interface)

U1 pin 12 (K2 /TX) and U1 pin 11 (/K2 RX) come from the K2's U6 MCU, 
pins 25
(TXD) and 26 (RXD) respectively. All of these pins are held near 5VDC 
until
they become active with data, at which time the level goes toward 
ground for
short duration pulses of data.

U1 pin 5 should be at -6 to -12VDC with no cable connected between the 
KIO2
and computer. If not, check for shorts on the pin or an unsoldered
connection. Use an ohmmeter to test for shorts with the power turned 
off.
Make sure you are counting the pins correctly. Make sure your serial 
cable
is built exactly like it is shown in the manual, and you did not 
miscount
the pins on the DB9 connectors. Male and Female DB9 connectors are 
mirror
images of each other.

Since the MCU in the K2 must be set up to use pin 25 as a data port, be 
sure
the sidetone and the SPOT button works in CW mode. Otherwise, U6 pin 25 
may
be setup as the sidetone source and not as a data pin. It is changed 
between
the two, by editing the ST L Menu entry and pressing the DISPLAY button
until U8-4 is seen rather than U6-25. You may have to switch off the 
power
after you make this change if the sidetone still doesn't work, and 
repeat
the process several times if it is unsuccessful.

Once you get the proper 5V level on the KIO2's U1 pins 11 and 12, you 
can
use an oscilloscope or even the lower AC volts range on a voltmeter to 
see
if data is present when you send a command from the PC or the K2. You 
can
follow the data from the PC to the KIO2 to J1 pin 3, U1 pin 6, then U1 
pin
11. Note that the small RF chokes on the KIO2 are fragile and can break 
so
they are an open circuit. Use an ohmmeter to verify all of them have 
less
than 10 ohms series resistance with the power turned off.

Look for wiring problems too, and small strands of wire on the boards 
(or
the cable connectors) that might be causing shorts to nearby circuits.
Reheat or resolder the connections if necessary.

The idea here, is to verify there is data coming from the PC to the 
MAX1406,
and then it is making it through U1 to the K2's MCU. Study the signal 
labels
and pins names on J1 and U1 on the KIO2 or KPA100 schematic and you 
should
be able to understand the data flow.

Example: TXD on J1 pin 2 means transmit data from the KIO2 to the PC. 
RXD on
J1 pin 3 means receive data from the PC to the KIO2.  U1 buffers this 
data
and then sends or receives it to/from the K2 MCU on the U1 pins labeled 
/K2
TX and /K2 RX. The "/" indicates these are active low pins, normally 
held
near 5VDC until data is present.

--
73, Gary AB7MY
=========
gary at elecraft.com
Elecraft Technical Support 
 



-----Original Message-----
From: Don Wilhelm [mailto:w3fpr at earthlink.net]
Sent: Friday, October 27, 2006 4:23 PM
To: james1787 at aol.com; elecraft at mailman.qth.net
Cc: support at elecraft.com
Subject: RE: [Elecraft] KIO2 sends out to pc but doesn't take commands 
from
pc


James,

Have you checked the resistance across the tiny inductors on the KIO2 
board?
Those inductors are easily damaged when installing, and an open inductor
would cause exactly the symptoms you report. RXD and TXD are separate
signals, so it is quite possible that TXD is working, but RXD is not -
resulting on 'one-way' communications.

73,
Don W3FPR


> -----Original Message-----
>
> I have been working with the KIO2 for a while to try to get it to
> work. It's never really worked since I put it in.
>
> Today I verified with another PC that the K2 does indeed send data
> through the KIO2 but it does not receive. I ran the test as described
> on page 14 of the KIO2 manual. Steps 1,2,3,4 works fine I get the
> FA0xxxxxxxx; to come up in hyperterminal when I hit the DISPLAY 
button
> as instructed. When I try step 5, which is to type SW01; then nothing
> happens. The software I tried cannot connect to the K2 either.
>
> The settings on my serial port (COM1) in Device manager (windows 2003
> production) are as follows:
> Bits Per Second: 4800
> Data Bits: 8
> Parity: None
> Stop Bits: 2
> Flow Control: None
>
> I am still baffled by what would cause one way communication, but not
> two way communication between the K2 and the PC.
>
> 73,
>
> James KB2FCV
>

--
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Checked by AVG.



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