Keysight Technologies E5260 Series, Programming Manual

Page: 52 / 350

1- 40 Keysight E5260/E5270 Programming Guide, Edition 4
Programming Basics
Status Byte
The status byte register can be read with either a serial poll or the *STB? query
command. Serial poll is a low-level GPIB command that can be executed by the
SPOLL
command in HP BASIC, for example
Status=SPOLL(@E5270)
.
In general, use serial polling (not *STB?) inside interrupt service routines. Use
*STB? in other cases (not in interrupt service routine) when you want to know the
value of the Status Byte.
NOTE If Bit 3, Bit 5, or Bit 7 are masked, they are not set to “0” by a serial poll. Also, if
these bits are masked, set to “1”, and then unmasked, a serial poll does not set them
to “0”.
After a masked bit is set to “1”, removing the mask does not set Bit 6 to “1”. That is,
the E5260/E5270 does not send an SRQ to the controller. Therefore, if you remove a
mask from a bit, it is usually best to do it at the beginning of the program.
5 32 Error
Indicates whether any error has occurred. If an error
occurred, this bit is set to “1”. It is set to “0” when the
E5260/E5270 receives a serial poll, *RST, ERR?, CA,
*TST?, *CAL?, DIAG? or device clear command.
6 64 RQS (You cannot mask this bit.)
Indicates whether an SRQ (Service Request) has occurred.
This bit is set to “1” whenever any other unmasked bit is
set to “1”. This causes the E5260/E5270 to send an SRQ to
the controller. It is set to “0” when the E5260/E5270
receives a serial poll, *RST, or device clear command.
7 128 Shutdown
If the E5260/E5270 turned off by itself to avoid damage, or
an instantaneous power down occurred on the site power
line, this bit is set to “1”. It is set to “0” when the
E5260/E5270 receives a serial poll, *RST, or device clear
command.
Bit
Decimal
Value
Description