Checking 5520A Status; Serial Poll Status Byte (Stb) - Fluke 5520A Operator's Manual

5-42. Checking 5520A Status

The programmer has access to status registers, enable registers, and queues in the
Calibrator to indicate various conditions in the instrument as shown in Figure 5-8. Some
registers and queues are defined by the IEEE-488.2 standard. The rest are specific to the
Calibrator. In addition to the status registers, the Service Request (SRQ) control line, and
a 16-element buffer called the Error Queue provide status information. Table 5-11 lists
the status registers and gives the read/write commands and associated mask registers.
Status Register

Serial Poll Status Byte (STB)

Service Request Enable Register (SRE)
Event Status Register (ESR)
Event Status Enable Register (ESE)
Instrument Status Register (ISR)
Instrument Status Change Register (ISCR)
ISCR 1 to 0 transition
ISCR 0 to 1 transition
Instrument Status Change Enable Register (ISCE)
ISCE 1 to 0 transition
ISCE 0 to 1 transition
Each status register and queue has a summary bit in the Serial Poll Status Byte. Enable
registers are used to mask various bits in the status registers and generate summary bits
in the Serial Poll Status Byte. For IEEE-488 interface operation, the Service Request
Enable Register is used to assert the SRQ control line on detection of any status
condition or conditions the programmer chooses. For RS-232 interface operation, the
SRQSTR string is sent over the serial interface when the SRQ line is set. (See the
SRQSTR command description in Chapter 6 for more information.)
5-43. Serial Poll Status Byte (STB)
The Calibrator sends the serial poll status byte (STB) when it responds to a serial poll.
This byte is cleared (set to 0) when the power is turned on. The STB byte is defined as
shown in Figure 5-9. If you are using the RS-232 as the remote control interface,
transmitting the ^P character (in the Terminal mode, hold down the <Cntl> key and press
P) returns the SPLSTR (Serial Poll String) and the status byte. Refer to the *STB
command, and for RS-232 interface operation, the SPLSTR and SPLSTR? commands,
in Chapter 6 for more information.
Table 5-11. Status Register Summary
Remote Operation
Checking 5520A Status
Read Write
Command Command

*STB?
*SRE? *SRE

*ESR?
*ESE? *ESE

ISR?

ISCR?

ISCR0?

ISCR1?
ISCE? ISCE
ISCE0? ISCE0
ISCE1? ISCE1
5
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