Specifications

Enabling Events to
be Reported in the
Status Byte
There are two sets of registers that individual status conditions must pass through
before that condition can be recorded in a group’s Event Register. These are the
Transition Filter Registers and the Enable registers. They provide selectivity in
recording and reporting module status conditions.
Configuring the
Transition Filters
Figure 3-12 shows that the Condition Register outputs are routed to the input of the
Negative Transition and Positive Transition Filter Registers. For space reasons they
are shown together but are controlled by individual SCPI commands. Here is the
truth table for the Transition Filter Registers:
Condition Reg Bit PTRansition Reg Bit NTRansition Reg Bit Event Reg Input
0®1
000
1®0
000
0®1
101
1®0
100
0®1
010
1®0
011
0®1
111
1®0
111
The Power-on default condition is: All Positive Transition Filter Register bits set to
one and all Negative Transition Filter Register bits set to 0. This applies to both the
Operation and Questionable Data Groups.
An Example using the Operation Group
Suppose that it is necessary for a module to report via the Status System when it
had completed executing the *CAL? operation. The “Calibrating” bit (bit 0) in the
Operation Condition Register goes to 1 when *CAL? is executing and returns to 0
when *CAL? is complete. In order to record only the negative transition of this bit
in the STAT:OPER:EVEN register, send:
STAT:OPER:PTR 32766 All ones in Pos Trans Filter
register except bit 0=0
STAT:OPER:NTR 1 All zeros in Neg Trans Filter
register except bit 0=1
Now when *CAL? completes and Operation Condition Register bit zero goes from
1 to 0, Operation Event Register bit zero will become a 1.
Configuring the
Enable Registers
Note in Figure 3-12 that each Status Group has an Enable Register. These control
whether or not the occurrence of an individual status condition will be reported by
the group’s summary bit in the Status Byte.
Questionable Data Group Examples
To have only the “FIFO Overflowed” condition reported by the QUE bit (bit 3) of
the Status Byte, execute:
STAT:QUES:ENAB 1024 1024=decimal value for bit 10
Programming the VT1419A Multifunction
Plus
Using the Status System
Chapter 3 91
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