American Magnetics 286 Multi-Sensor Liquid Level Instrument (CE-Marked) - Manual (Page 78)

64
Remote Interface Reference
SCPI Status System
•
A *CLS command is executed.
•
The Standard Event register is read (only bit 5 of the Status Byte
register is cleared).
•
The indicated condition no longer exists.
•
The power is turned off and then back on.
The Status Byte enable register is cleared when any of the following occurs:
•
The *SRE 0 command is executed.
•
The power is turned off and then back on.
5.2.2.2 Reading the Status Byte using *STB?
The *STB? query returns the contents of the Status Byte register, but it is
processed in the command queue like any other command. The *STB?
query returns the same result as a Serial Poll; however, bit 6 of the Status
Byte register is not cleared. Issuing an
*STB? query does not clear an SRQ
condition.
5.2.2.3 Using the Message Available Bit
The “Message Available” bit (bit 4) of the Status Byte register can be used
to determine when data is available to read into your host computer. The
instrument clears the “Message Available” bit only after all data has been
read from the output buffer.
The “Message Available” bit of the Status Byte register is useful for
determining if queries have executed; however, they are not useful alone
for determining if commands have completed execution, since commands
do not provide return data.
5.2.3 Standard Event Registers
The Standard Event register group reports a power-on condition, reports
various error conditions, and indicates when an operation has completed.
Any or all of the Standard Events can be reported to the Status Byte
register by enabling the corresponding bit(s) in the Standard Event enable
register (see Figure 5-1). To set the Standard Event enable register, write
a binary-weighted decimal value using the
*ESE < value > command.
The bit definitions for the Standard Event register are provided in
Table 5-2. To query the instrument for the details of a reported error in the
Standard Event register, use the
SYSTem:ERRor? query. See paragraph
5.5 for a complete discussion of the error buffer and messages.
The Standard Event register is cleared when any of the following occurs:
•
The *CLS (clear status) command is executed.