Edwards SCU-350 Series

SCU-350 Series Control Unit for Turbomolecular Pump
MT-21E-201-E
Page 70
5
SERIAL COMMUNICATION PROTOCOL
5.4.2 Error message
Each query or command sets the error number to indicate success or the reason for failure. The error
number is returned by any command. If a query is in error (for example a parameter number is out of
range) then instead of the normal reply, a message of the form "ERR n" is sent, where "n" is the error
number.
Error number Meaning
0 No error
1 Not a valid query or command
2
Number not found - needed as part of
query or command
3 Number not in valid range
4 Parameter’s value not received by SIM
Note: When the STP pump is in the abnormal (alarm) state, the STP pump cannot start before
resetting the state. In this case, message should be "ERR 1".
Note: To reset alarm state, "!R" command is needed. But in some case, the alarm state cannot be
reset because of the hard ware reason. In this case, the message should be "ERR 1".