Eye Diagram Diagnosis

Function

Diagnose the signal quality and output the diagnosis result.

**Table 1** Diagnostic items
Item	Time Required	Whether NPU Training or Inference Is Affected	Application Scenario
signalQuality	10s~2min	No	A PCIe, HCCS, RoCE, UB link fault occurs on a training or inference job.

Parameters

Table 2 lists only test-specific parameters. For details about other common parameters, see Common Parameters.

**Table 2** Parameter description
Parameter	Description	Mandatory
[-i, --items]	Specifies the diagnosis check item. signalQuality indicates signal quality diagnosis of PCIe, HCCS, RoCE, and UB.	Yes
[-lt, --lt, --link-type]	Specifies the link type for eye diagram diagnosis. The options are as follows: hccs: eye diagram diagnosis of the HCCS link; supported by the Atlas 300I Duo inference card, Atlas A2 training product, Atlas 800I A2 inference server, A200I A2 Box heterogeneous component, Atlas A3 inference product, and Atlas A3 training product; not supported by the Atlas 800I A2 inference server (32 GB PCIe). pcie: eye diagram diagnosis of the PCIe link; supported by the Atlas 300I Duo inference card, Atlas A2 training product, Atlas 800I A2 inference server, A200I A2 Box heterogeneous component, A200T A3 Box8 SuperPoD Server, and Atlas 350 accelerator card. When only the secondary chip is specified for the Atlas 300I Duo inference card, the signal quality of the PCIe link is not diagnosed. roce: eye diagram diagnosis of the RoCE link; supported by theAtlas A2 training product, Atlas 800I A2 inference server, A200I A2 Box heterogeneous component, Atlas A3 inference product, Atlas A3 training product, and Atlas 850E/Atlas 650E server. ub: eye diagram diagnosis of the UB link; supported by the Ascend 950PR and 950DT products.	No

Example

ascend-dmi -dg -i signalQuality --link-type hccs,pcie

[***@***]# ascend-dmi -dg -i signalQuality --link-type hccs,pcie
Summary:
    Arch: aarch64
    Mode: ******
    Time: 20250529-19:24:32
 
Hardware:
    signalQuality:
        PASS

Fault Check Items

**Table 3** Fault check items
Command Output	Description
PASS	The check is passed, and the signal quality is normal.
SKIP	The eye diagram diagnosis is not supported. The link type specified by link-type is not supported.
IMPORTANT_WARN	Important warning. Abnormal signal quality is detected on PCIe, HCCS, RoCE, or UB (one or more of these). Contact Huawei engineers for assistance.
FAIL	The eye diagram detection fails.
Note: In the SignalQuality diagnosis, for the Ascend 950PR and 950DT products, an SNR value of 0 indicates that a link has not been established between the specified devices. For other products, SNR and HEH values of 0 indicate that a link has not been established between the specified devices.

Parent topic: Health Check