Measurement Computing DAC488 v.1 - Manual (Page 70)

64 DAC488 Commands DAC488 User’s Manual
E? - Query Error Status
TYPE System Command
SYNTAX E? Return and clear present error condition. After execution of Error Query
command, DAC488 will return one of the following error codes:
•
E0 if No Error has occurred.
•
E1 if Unrecognized command (e.g. Z4X ).
•
E2 if Invalid Command Parameter (e.g. A62X, C10X ).
•
E3 if Command Conflict Error (e.g. A1 R2 ).
• E4 if Calibration switch not closed.
•
E5 if Non-Volatile RAM error, system defaults or Calibration Constants may
be lost.
DESCRIPTION
The Error Query command is used to determine the present error condition on the selected port of the DAC488. After
execution of the Error Query command, the present error condition is cleared. The error condition is also cleared by
executing the Status (U0) command. When an error has occurred, the ERROR LED on the DAC488 front panel will
turn on. The ERROR LED will stay on until an Error Query (E?) or Status (U0) command is executed.
If a Calibration Write Protected Failure (E4) occurs, this error condition may also be cleared by executing the Error
Query (E?) command. This type of error occurs when an attempt is made to save Calibration Constants without first
setting the calibration switch on the back panel to the depressed position.
If a Non-Volatile RAM error (E5) occurs on power up, the S? command may be used to check the system defaults.
One of the following responses will be returned:
•
S0 = Factory defaults are in use, user programmed defaults were lost
•
S1 = User programmed defaults are still valid
The Calibration Constants may be tested by issuing the following command string: A0 R0 X J?. One of the
responses below will be returned:
•
J128,128 = Factory Calibration Constants are in use, Calibration Constants which were saved from a calibration
procedure have been lost. The DAC488 should be recalibrated if this response is returned.
•
J127,127 = Calibration Constants which were saved from a calibration procedure are still valid.
Note: After execution of the Error Query command, the present error condition is cleared.
EXAMPLE 1: No error.
PRINT#1,"CLEAR09" Line 1: Reset the DAC488.
PRINT#1,"OUTPUT09;E?" Line 2: Request error status.
PRINT#1,"ENTER09"
INPUT#2,A$
PRINT A$ Line 5: Display shows E0, no errors have occurred.
EXAMPLE 2: Invalid Command Parameter.
PRINT#1,"OUTPUT09;C0 P1
A0 R1 V3 X"
Line 1: Select Direct Control mode, select Port 1, disable autoranging, select
±
1 volt range, output 3 volts. ERROR LED on DAC488 should turn on after
this command string is executed.
PRINT#1,"OUTPUT09;E?" Line 2: Request error status.
PRINT#1,"ENTER09"
INPUT#2,A$
PRINT A$ Line 5: Display shows E2 (invalid command parameter) since an attempt was
made to output 3 volts on the 1 volt range. The V3 command caused the
error since valid voltage values for the 1 volt range must be between -1 and 1
volt.
EXAMPLE 3: Unrecognized Command. (See next page.)