Answer
If you get a communication alarm on the Driver object, the help text appears correctly. But if you get the alarm on the node status object, you get an error message from the help system.
The workaround for this problem is to write down the error code shown in the “Value” field for the node status object. Right-click the alarm again and select “Driver Help” to open the driver-specific help file, DrvSpec3.hlp. On the “Contents” tab, find the relevant driver. Open its book and then open the “Driver-Specific Error Codes” book and find the error code in question.