Tektronix PWS4205, Programmer'S Manual

Page: 68 / 90

Status and Events
Table 3-4: QCR bit functions (cont.)
Bit Function
2 UNR
Unregulated.
Indicates that the power supply has gone
out of regulation.
1 OT
Over Temperature.
Indicates that the power supply
has experienced an over temperature condition and the
output has been shut down.
0 (LSB) OV
Over Voltage.
Indicates that the overvoltage protection
threshold has been exceeded and the output has shut down.
The Questionable Positive Transition Register (QPTR) and Questionable Negative
Transition Register (QNTR).
The QEVR can be con fi gured to respond to speci fi c
transitions in the QCR. The transitions and the polarity of these transitions are
speci
fi ed in the QPTR and QNTR. These registers act as
fi lters between the QCR
and the QEVR. If a bit is set to 1 in the QNTR, the corresponding bit in the QEVR
will be set to 1 whenever the same bit in the QCR makes a negative transition,
from 1 to 0. If a bit is set to 1 in the QPTR, the corresponding bit in the QEVR will
be set to 1 when the same bit in the QCR makes a positive transition, from 0 to 1.
The Questionable Event Register (QEVR).
The Questionable Event Register is
made up of eight bits, which have the same signi fi cance as the QCR, but have
been fi ltered by the QPTR and QNTR.
Enable Registers There are four types of enable registers:
Event Status Enable Register (ESER), (See page 3-7.)
Service Request Enable Register (SRER), (See page 3-7.)
Operation Enable Register (OENR), (See page 3-7.)
Questionable Enable Register (QENR), (See page 3-7.)
ESER, SRER, OENR, and QENR allow you to select which events are reported to
the Status Byte Register (SBR).
Each bit in an Enable Register corresponds to a bit in an Event Register. In order
for an event to be reported to a bit in the Status Byte Register, the corresponding
bit in the Enable Register must be set to one. If the bit in the Enable Register is set
to zero, the event will not affect the status bit.
Various commands set the bits in the Enable Registers. The Enable Registers and
the commands used to set them are described below.
3-6 PWS4205, PWS4305, PWS4323, PWS4602, and PWS4721 Power Supply Programmer Manual