The Compax3's error log can be uploaded (read) by a device connected to its RS232/485 port. It can also be viewed in C3 ServoManager's Optimization Screen by clicking the icon looking like a computer with an Up Arrow. The most recent error is displayed on the top (number 1), and the 30 previous errors are displayed below it. The errors do not have a timestamp.
To get the most recent error from the Compax3, have your RS232 device send the string "ro550.1" (or, from the Optimization Screen, type ":ro550.1"). This will return the decimal number corresponding to the last error (see the C3 Error List in the User Manual). Objects 550.2 through 550.31 contain the 30 next most recent errors.
To clear the error log, send the string "wo551.1=-1" . Or, from the Optimization Screen, in the lower-left corner, type ":wo551.1=-1".
Multiple errors can be present. They are separated by the 0001 QUIT which is an error acknowledgement.
5/19/16jh added related FAQ link and image