ESR and ESE
The event status register (ESR) indicates general instrument states. It is linked to the standard event status enable (ESE) register on a bit-by-bit basis.
The ESR corresponds to the CONDition part of a SCPI register indicating the current instrument state. However, reading the ESR deletes the contents.
The ESE corresponds to the ENABle part of a SCPI register. If a bit is set in the ESE and the associated bit in the ESR changes from 0 to 1, the ESB bit in the status byte is set.
Bit | Weight | Meaning |
---|---|---|
0 | 1 | Operation complete This bit is set on receipt of the *OPC command after all previous commands have been executed. |
1 | 2 | Request control This bit is set if the instrument requests the controller function. Example: The instrument sends a hardcopy to a printer or a plotter via the IEC-bus. |
2 | 4 | Query error This bit is set if the controller wants to read data from the instrument without having sent a query. It is also set if the controller does not fetch requested data and sends new instructions to the instrument instead. The cause is often a query which is faulty and hence cannot be executed. |
3 | 8 | Device-dependent error This bit is set if a device-dependent error occurs. An error message with a number between -300 and -399 or a positive error number, which describes the error in greater detail, is entered into the error queue. |
4 | 16 | Execution error This bit is set if a received command is syntactically correct, but cannot be performed for other reasons. An error message with a number between -200 and -300, which describes the error in greater detail, is entered into the error queue. |
5 | 32 | Command error This bit is set if a command which is undefined or syntactically incorrect is received. An error message with a number between -100 and -200, which describes the error in greater detail, is entered into the error queue. |
6 | 64 | User request This bit is set when the LOCAL key is selected on the instrument, i. e. when the instrument is switched to manual control. |
7 | 128 | Power on (supply voltage on) This bit is set when the instrument is switched on. |
The event status register (ESR) can be queried using *ESR? command.
The standard event status enable (ESE) register can be set using the *ESE command and read using *ESE? command.