我进行mod和demo时，gr-tnc解帧器输出XXX

Question

我在使用gr-tnc OOT恢复消息时遇到问题。当我在禁用HDLC编码器加扰器的情况下运行ax25_framer_deframer_test示例时，消息调试显示重复的X。

请参见以下禁用香草示例加扰器的屏幕截图：

Generating: '/home/<my path>/gr-tnc/examples/ax25_test/top_block.py'
>>> Warning: This flow graph may not have flow control: no audio or RF hardware blocks found. Add a Misc->Throttle block to your flow graph to avoid CPU congestion.

Executing: /usr/bin/python2 -u /home/<my path>/gr-tnc/examples/ax25_test/top_block.py

XXXXXX
>>> Done (return code -15)

但是，当我禁用加扰器时，会得到如下所示的漂亮输出：

Generating: '/home/<my path>/gr-tnc/examples/ax25_test/top_block.py'
>>> Warning: This flow graph may not have flow control: no audio or RF hardware blocks found. Add a Misc->Throttle block to your flow graph to avoid CPU congestion.

Executing: /usr/bin/python2 -u /home/<my path>/gr-tnc/examples/ax25_test/top_block.py

********Deframer: * MESSAGE DEBUG PRINT PDU VERBOSE *
 ()
pdu_length = 1529678485.0550
contents = 

0000: d0 22 e7 d5 20 f8 e9 38 a1 4e 18 8c 47 30 8c fe 
0010: f5 ff f7 f7 28 b9 f8 fb f5 1c 7c cc cc 4c 24 01 
0020: 6b 1c ea a3 ca e0 f5 80 a7 cc 09 5c d9 36 ef ae 
0030: ad 66 
***********************************
********Deframer:  1529678486.05
* MESSAGE DEBUG PRINT PDU VERBOSE *
()
pdu_length = 50
contents = 
0000: c1 bd be 79 64 6c a7 2c 2b 4d b4 cc 08 51 46 df 
0010: 0b 26 18 fe d2 d2 b1 20 51 c3 f3 7d 08 a9 70 20 
0020: 61 35 c3 0d cb 09 2f 68 7d 75 72 7c a5 cb b5 eb 
0030: c1 ce 
***********************************
********Deframer: * MESSAGE DEBUG PRINT PDU VERBOSE *
 1529678487.05
()
pdu_length = 50
contents = 
0000: 46 b4 ae 00 a7 b5 29 a4 1e 74 7f c6 f5 92 57 e0 
0010: 95 ce 39 04 c0 d2 41 d2 81 f0 b2 69 e4 6c f5 94 
0020: 8c 28 23 c3 26 3a 41 cf d7 fd 41 55 d0 4c 3e 03 
0030: ed 37 
***********************************

>>> Done (return code -15)

现在，当我通过GMSK链接发送和接收消息时，与关闭扰码器后出现的错误类似“ Xs”。

通过GMSK链接（打包和解包）：

Generating: '/home/<my path>/gr-tnc/examples/ax25_test/top_block.py'

Executing: /usr/bin/python2 -u /home/<my path>/gr-tnc/examples/ax25_test/top_block.py

XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
>>> Done (return code -15)

如果我绕过包装和拆箱，我将根本无输出。

通过GMSK链接（未包装和未包装）]：

Generating: '/home/<my path>/gr-tnc/examples/ax25_test/top_block.py'

Executing: /usr/bin/python2 -u /home/<my path>/gr-tnc/examples/ax25_test/top_block.py


>>> Done (return code -15)

这些X是什么？基于未加密然后解码的消息是Xs的事实，我假设它们表示的字节格式不正确。但是，我不明白是什么原因导致它无法从调制和解调中恢复。

我在通过PyBombs安装了GNURadio的Ubuntu 16.04上，并具有GRC 3.7.12.0。

此外，我不得不修改gr-tnc源。我删除了一个损坏的import satisfi和from satisfi import ax25。

在此先感谢您提供所有帮助。

编辑：

1. 意识到我正在使用不同的样本/符号运行mod和demo，并修复了该问题，仍然获得了相同的输出。

2. 添加了有关修改grc-tnc源的注释。

3. 修正错字。