Cleanup

hugo/content/manual/knowledgebase/hardware/_index.md

@@ -8,3 +8,43 @@ chapter = false
 ## Topics
 {{% children %}}
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+
+### culprit
+
+From experience, very few issues are related to the EtherCAT hardware itself.
+Mostly the cabling or the actual motor/encoder hardware is to blame.
+
+Even more likely is human error, such as:
+* wrong scaling of the axis
+* writing to the wrong hardware (forgot to select the right slave in the axis config)
+* ...
+
+#### check the status
+Before anything is restarted or power cycled, check the status of the system.
+
+A simple way to get an overview of the entire ecmc system is to start the ecmcMain.ui panel. This panel contains, or links to, almost the entire ecmc IOC:
+* thread status
+* EtherCAT master status 
+* EtherCAT slaves status (overview of all configured slaves)
+* motion axes (all axes in the system are reachable)
+* PLC:s
+* ...
+
+```bash
+caqtdm -macro "IOC=<iocname>" ecmcMain.ui
+```
+
+Remember, `red` is not necessarily a bad sign!
+It can also indicate that certain channels are not connected.
+Whether those channels _should_ be connected is beyond the scope of this guide.
+
+Next step is to diagnose from a dedicated shell, or from within the `iocsh`.
+
+If all slaves are in 'OP' state, at least data is exchanged between the hardware and the master. 
+
+#### restarting the IOC
+{{% notice warning %}}
+Blindly restarting the IOC, with only partially working EtherCAT hardware, WILL RESULT IN TOTAL FAILURE OF THE IOC!!!
+{{% /notice %}}
+
+Check the hardware BEFORE restarting the IOC!