[Trlog] TRLog Linux Operation with HAL DXP38 Modem

[Wayne, W0ZW]

Here the next step in my debug process for configuring TRLog Linux to work with my HAL DXP38 modem.  

I needed a way to monitor what commands are being sent to the DXP38 from the trlog application.  To do this I installed a program called "interceptty"  (see https://github.com/geoffmeyers/interceptty ).   interceptty acts as a "middleman" between the DXP38 serial port and TRLog.  It creates a pseudo port, which is what TRLog now connects to in order to talk to the DXP38 and for interceptty to capture the traffic between the two.  Pretty slick.

Below is an initial capture of this serial communications between TRLog Linux and my DXP38.  The following text is the interceptty output to stdout.  I copied an excerpt of this data and pasted it below.  The left-most column is the traffic sent by TRLog to the DXP38.  The column to the right is data sent by the DXP38 to TRLog.  The comments bracketed by *** <  >*** are mine added afterwards to clarify what's happening.

The sequence below shows a correct interaction when I started TRLog, switched to digital mode and pressed the F1 key to send a RTTY CQ.  I truncated some of the random receive characters at the beginning and at the end for brevity:


> 	    0x4a (J)    *** Random RX characters from DXP38 ***
> 	    0x41 (A)
>   	    0x3a (:)
>   	    0x22 (")
> 	    0x24 ($)
>   	    0x33 (3)
>   	    0x34 (4)
> 	    0x24 ($)
< 0x80 (�)          *** 0x808E (RTTY SEND STRING) is command to DXP38 to begin RTTY TX ***
< 0x8e (�)
< 0x43 (C)          *** Beginning of TRLog F1 CQ message text to DXP38 ***
< 0x51 (Q)
< 0x20 ( )
< 0x54 (T)
> 	    0x80 (�)    *** DXP38 sends ack of 0x80 0x8E RTTY TX command ***
< 0x45 (E)
> 	    0x8e (�)
< 0x53 (S)
< 0x54 (T)
< 0x20 ( )
< 0x57 (W)
< 0x30 (0)
< 0x5a (Z)
< 0x57 (W)
< 0x20 ( )
< 0x57 (W)
< 0x30 (0)
< 0x5a (Z)
< 0x57 (W)
< 0x20 ( )
< 0x54 (T)
< 0x45 (E)
< 0x53 (S)
< 0x54 (T)
< 0x20 ( )
< 0x0d ([CR])
< 0x80 (�)          *** Half of 0x800E (RTTY RECEIVE STRING) TRLog cmd to DXP38 to switch to RX  ***
> 	    0x33 (3)
> 	    0x80 (�)    *** Status fm DXP38 0x807A 0x8006 (indicates switch to FSK TX mode) ***
> 	    0x7a (z)
> 	    0x80 (�)
> 	    0x06 ([ACK])
> 	    0x80 (�)    *** 0x8031 status fm DXP38 indicates echo of TX chars to follow ***
> 	    0x31 (1)
< 0x0e ([SO])       *** 2nd half of 0x800E cmd to DXP38 to go to RX ***
> 	    0x43 (C)    *** Continuation of echoed TX characters (F1 CQ msg) ***
> 	    0x51 (Q)
> 	    0x20 ( )
> 	    0x54 (T)
> 	    0x45 (E)
> 	    0x53 (S)
> 	    0x54 (T)
> 	    0x20 ( )
> 	    0x57 (W)
> 	    0x30 (0)
> 	    0x5a (Z)
> 	    0x57 (W)
> 	    0x20 ( )
> 	    0x57 (W)
> 	    0x30 (0)
> 	    0x5a (Z)
> 	    0x57 (W)
> 	    0x20 ( )
> 	    0x54 (T)
> 	    0x45 (E)
> 	    0x53 (S)
> 	    0x54 (T)
> 	    0x20 ( )
> 	    0x0d ([CR])
> 	    0x80 (�)
> 	    0x30 (0)
> 	    0x80 (�)
> 	    0x0e ([SO])
> 	    0x80 (�)        *** 0x8030 status fm DXP38 indicates RX chars to follow ***
> 	    0x30 (0)
> 	    0x80 (�)        *** Status fm DXP38 0x807A 0x8007 (indicates switch to FSK RX mode)
> 	    0x7a (z)
> 	    0x80 (�)
> 	    0x07 ([BEL])
> 	    0x80 (�)        *** 0x8030 status fm DXP38 indicates RX chars follow ***
> 	    0x30 (0)
> 	    0x43 (C)        *** Random RX chars from DXP38 ***
> 	    0x48 (H)
> 	    0x54 (T)
> 	    0x0d ([CR])
> 	    0x49 (I)
> 	    0x56 (V)
> 	    0x5a (Z)

The information above shows a correct data exchange between TRLog and my DXP38 modem.  It appears to show the correct use of the TRLog RTTY SEND STRING and RTTY RECEIVE STRING.  I have found that the first attempt generally works.  It is subsequent interactions involving F10, the Escape key and also S&P mode are when TRLog seems to get confused.

My next step is to configure interceptty to write the captured traffic to a file and then run TRLog and cause it to fail.  Hopefully I can find in the captured serial data an explanation for the failures that I have been seeing.  

73,
Wayne, W0ZW