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What kind of Cable for LK204-25

Posted: Thu Aug 09, 2007 5:33 am
by skaterzero807
Does anyone know if the serial cable used for power and communication through the db9 is a null-modem cable or just a pin-to-pin cable.

Posted: Thu Aug 09, 2007 7:29 am
by Raquel
Hello skaterzero807,

Thanks for your post.

The RX and TX lines in the power and communication cable are straight-thru (pin to pin). Please note that of course the connection depends on the serial cable that you will be connecting to the power and communication cable.

For the LK204-25 PCB 2.0, you will need a straight-thru cable.

I hope this helps,

Posted: Thu Aug 09, 2007 7:36 am
by skaterzero807
Yes. That helps very much. Thanks for the speedy reply.

The only thing I can't figure out now is how to issue commands to the module via the serial port. The documentation online tells you what the Hex, decimal and ascii codes are, but if I send the string "254 88" (clear screen) the numbers show up as if they were text. Is there a character I need to add to allow the module to know these numbers are commands and not text? In other words, what string would be appropriate to send to issue a command?

::edit::
If it is any help, I am using Visual Basic to send text through the serial port via the mscomm control

Posted: Thu Aug 09, 2007 8:41 am
by Raquel
Hello skaterzero807,

Sending 254, 88 to clear the screen is to send 2 data byte values: 254 and 88.
You see "254 88" on the screen because you are sending the ASCII values of each character, ie. you are sending 6 data bytes:
'2', '5', '4', <space>, '8', '8'

I hope this clears it out. Unfortunately, I am not familiar with Visual Basic, hopefully somebody out there can help.

Best Regards,

Posted: Thu Aug 09, 2007 8:52 am
by skaterzero807
Ok. Thank you for clearing that up. I was merely omitting the comma then. Thank you so much for your help.