---
title: 未配置环回，执行码流测试或诊断时报错-8005、-8001
description: "执行码流测试或诊断，报错如下。"
url: https://www.hiascend.com/document/detail/zh/mindcluster/latest/toolbox/toolboxug/toolboxug_0235.html
sourcePath: /source/zh/mindcluster/2610/toolbox/toolboxug/toolboxug_0235.html
indexId: fceba6409f87cf6abc8c9bf7e429cd27270cd862642537d1d9485e8e8eea6fd265
---
# 未配置环回，执行码流测试或诊断时报错-8005、-8001

#### 问题现象

执行码流测试或诊断，报错如下。
```
[****@******]# ascend-dmi --dg -i prbs -q
Summary:
Arch: aarch64
Mode: *****
Time: 20250414-15:16:43
Hardware:
prbs:
FAIL
*** error occurred on device 0
*** error occurred on device 1
```


查看日志，报错如下。

```
[WARN][2025-04-14 15:15:46][76270][prbs_thread.cpp ControlTransPrbsCodeStream:86] call dcmi_prbs_operate failed. type=8, direction=1, cardId=3, chipId=0, ret=-8005
[WARN][2025-04-14 15:15:46][76270][prbs_thread.cpp ExecPrbsCodeStream:229] start prbs trans failed on device 3
[WARN][2025-04-14 15:15:47][76270][prbs_thread.cpp ControlTransPrbsCodeStream:86] call dcmi_prbs_operate failed. type=8, direction=1, cardId=6, chipId=0, ret=-8001
[WARN][2025-04-14 15:15:47][76270][prbs_thread.cpp ExecPrbsCodeStream:229] start prbs trans failed on device 6
```


#### 可能原因

驱动版本在25.0.RC1及以上，未配置环回，开启打流时校验SNR不通过。


#### 解决措施

配置CDR环回或外接光纤回路器，待网口up后，重新执行打流操作。