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possible reasons for cryptic characters in Minicom output

I'm using Minicom 2.3:

Code:

[root@ ~]# minicom -v

minicom version 2.3 (compiled Oct 22 2009)

Copyright (C) Miquel van Smoorenburg.



This program is free software; you can redistribute it and/or

modify it under the terms of the GNU General Public License

as published by the Free Software Foundation; either version

2 of the License, or (at your option) any later version.



[root@ ~]#

..under OpenSUSE:

Code:

[root@ ~]# uname -a

Linux pc 2.6.31.5-0.1-default #1 SMP 2009-10-26 15:49:03 +0100 i686 i686 i386 GNU/Linux

[root@ ~]#

The problem is that if I try to connect to one specific radio device over it's console port, I see only cryptic characters in Minicom output:

Example 1:

Quote:

Welcome to minicom 2.3

OPTIONS: I18n
Compiled on Oct 24 2009, 03:01:06.
Port /dev/ttyUSB0

Press CTRL-A Z for help on special keys

PS7=05S =1T!P4C1E!A0

Welcome to minicom 2.3

Example 2:

Quote:

Welcome to minicom 2.3

OPTIONS: I18n
Compiled on Oct 24 2009, 03:01:06.
Port /dev/ttyUSB0

Press CTRL-A Z for help on special keys

AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0

I have tried with every baud rate under "Serial port setup". According to documentation this radio device has 19200 8N1 "no data flow control" RS232 setup by default. The pinout is correct because I see the DE9<->USB adapter Tx and Rx LEDs blinking if a press any key on my keyboard.

Are there any other reasons/situations other than wrong speed that one can see a cryptic characters in Minicom output? :rolleyes:

Those look (at least the second example) to be AT commands, strings that are used to configure serial modems. Have you checked in the Minicom configuration to make sure you have disabled all AT commands for these particular devices? By default, Minicom will attempt to send the device various AT commands to configure it during the connection, which in this case won't do anything but clutter the screen with annoying text.

Quote:

Originally Posted by MS3FGX (Post 4473925)

indeed :) Under "Modem and dialing" configuration I have a following "Init string":

Code:

~^M~AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0^M

..which is exactly the one printed by Minicom. Thanks for pointing this out! However, how could this modem init string sent by Minicom interfere the serial communication? I mean even if I empty the "Init string", how could this help to establish serial communication with this radio device I mentioned? Because I don't mind the modem initialization sequence printed- the main goal is to establish a communication with the radio device over console port but I'm out of ideas because the speed and other parameters seem to be correct and two-way communication works, but still I don't get the command prompt of the radio device :rolleyes:

Sending an unexpected string of seemingly random characters to a device is not a good way to start communications with it; there is no telling how it will react.

Quote:

Originally Posted by MS3FGX (Post 4475339)

Sending an unexpected string of seemingly random characters to a device is not a good way to start communications with it; there is no telling how it will react.

I tried with "19200 8N1"(no "Hardware Flow Control" and no "Software Flow Control") settings and using the empty modem "init string", but still nothing :rolleyes: If I press any key on my keyboard, I see both Rx and Tx led blink on my DE9<->USB RS232 adapter. Any other suggestions, what might be the problem?