Checking 5500A Status; Serial Poll Status Byte (Stb) - Fluke 5500A Operator's Manual

5-42. Checking 5500A Status

The programmer has access to status registers, enable registers, and queues in the 5500A
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.

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 5500A 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 value of this byte at
power-on is determined by the value of the service request enable register (SRE), which
is saved in nonvolatile memory. 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
Status Register
Remote Operation
Checking 5500A Status
Read Write
Command Command
*STB?
*SRE? *SRE
*ESR?
*ESE? *ESE
ISR?
ISCR?
ISCR0?
ISCR1?
ISCE? ISCE
ISCE0? ISCE0
ISCE1? ISCE1
5
5-35