HP 70340A, User Manual

Page: 343 / 445

Note that eac h status group do es not necessarily con tain all of the registers sho wn in
Figure 7-2 . F or example, the Standard Ev en t status group only con tains an Ev en t Register
and an Enable Register. Eac h of the Signal Generator status groups consists of some or all of
the registers explained b elow:
Condition Register
A condition register con tinuously monitors the hardw are and rm w are status of the Signal
Generator. There is no latching or buering for a condition register; it is up dated in real time.
Negativ e Transition Register
A negative transition register sp ecies the bits in the condition register that will set
corresp onding bits in the ev en t register when the condition bit c hanges from 1 to 0.
P ositiv e Transition Register
A p ositiv e transition register sp ecies the bits in the condition register that will set
corresp onding bits in the ev en t register when the condition bit c hanges from 0 to 1.
Ev ent Register
An ev en t register latches transition ev en ts from the condition register as sp ecied b y the
p ositiv e and negative transition registers. Bits in the ev en t register are latched, and once set,
they remain set un til cleared b y either querying the register con ten ts or sending the \*CLS"
command.
Enable Register
An enable register sp ecies the bits in the ev en t register that can generate a summary bit.
The Signal Generator logically ANDs corresp onding bits in the ev en t and enable registers, and
ORs all the resulting bits to pro duce a summary bit. Summary bits are, in turn, used b y the
Status Byte group.
Signal Generator Status Groups
The Signal Generator status register system consists of the Status Byte group and three other
status groups that pro vide input to the Status Byte group. The following paragraphs explain
the information that is pro vided b y eac h status group.
The Status Byte Group
The Status Byte group is used to determine the general nature of an instrumen t ev en t or
condition. The Status Byte group consists of the Service Request Enable register and the
Status Byte. The bits in the Status Byte pro vide y ou with the following information:
Bit Description
0 - 2 These bits are alwa ys set to 0.
3 A 1 in this bit p osition indicates that the Questionable Data summary bit has b een
set. The Questionable Ev en t register can then b e read to determine the sp ecic
condition that caused this bit to b e set.
Programming Commands 7-119
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com