3KP78 - 1.7
3000PLUS
WITH
5D78 I
NSTRUCTION
M
ANUAL V
. SB.3
1. I
NTRODUCTION
• Channel 2
—the “auxiliary” DAC output, which con-
tinuously operates on Channel 1 for purposes of
limit evaluation, peak capture, tare offset, etc. It is
produced for display, interrogation via the
CHN
command, and generation of the “raw volts” analog
output (Channel 3).
• Channel 3
—the instrument’s “scaled voltage” out-
put, which is continuously proportional to Channel 2.
It may be set to a full scale of either ±5 or ±10 VDC,
and is available at the rear of the 3000PLUS as both
DC voltage and 4-20 mA output (see Section 2.D)
As explained in the following section, the front-panel
SCROLL
button may be used during normal run-time
operation to cycle through the three channel displays.
4
When Channel 2 or 3 is being displayed, the corre-
sponding front-panel indicator LED (
C2
or
C3
) will
light—see Fig. 2. No indicator lights when Channel 1 is
displayed.
The channel that is displayed whenever the 3000PLUS
is powered up is always the channel that was on dis-
play when the meter was last turned off.
C
OMMUNICATIONS
I
NDICATION
Fig. 2 also shows the 3000PLUS instrument’s front-
panel
CM
LED. This indicator lights when the RS232
serial communications port (Section 2.B) is in receipt of
one or more transmitted ASCII characters (which may
or may not constitute a valid MNEMONIC COMMAND—
see Appendix A).
L
IMIT
S
TATUS
I
NDICATION
Whenever continuous limit monitoring of the “auxiliary”
output (Channel 2) is enabled, the appropriate front-
panel limit status indicator (Fig. 2) will show the
LIMIT
ZONE
in which Channel 2’s existing data reading lies
(regardless of whether Channel 2 is the one currently
D
ATA
D
ISPLAY
Updated four times a second, the 3000PLUS instru-
ment’s six-digit data LED data display is automatically
scaled to count by a resolution of 1, 2, or 5 to a maxi-
mum reading of ±199990.
1
Regardless of the scaling
currently in effect, a flashing display during normal run-
time operation indicates that an overrange condition
has occurred. In this case, the displayed measurement
reading may be invalid.
During normal instrument setup, the operator will be
called upon to indicate the
DESIRED FULL-SCALE
READING IN ENGINEERING UNITS
(the “FULL SCALE
UNITS” or “FSU” value), to correspond to a full-scale
output of 5.000 volts. This can be done via the front-
panel setup procedure (as explained in Section 3.B) or
via the Configurator software, on a setup or run-time
basis (as explained in Section 4). The
DECIMAL-
POINT RESOLUTION
of the data display for Channels
1 and 2 will always match that of the last-entered FSU
value.
2
You can also specify a
DISPLAY OFFSET
value
(“DSO”), if desired—again, either through the front panel
or the Configurator software. The DSO is a value of
numeric offset (positive or negative) to be continuously
applied to the displayed reading of Channel 1 or 2 (see
below). Note that the DSO is applied in addition to any
zero offset resulting from instrument calibration (Sec-
tions 3 and 4) and to any specified tare offset (Section
5.D).
3
In addition to the normal-mode analog filtering fur-
nished by the installed 5D78 Conditioner, the 3000PLUS
can apply selectable
DIGITAL FILTERING
(“DFL”) to the
data display to allow smooth, stable readout of dynamic
variables. The DFL number ranges from 0 through 9 to
indicate increasing amounts of digital smoothing. Like
the FSU and DSO values, it may be entered through
either the front panel or the Configurator software.
Use of the data display for manual setup of the
3000PLUS instrument is described in detail in Section 3
(“Front-Panel Configuration and Calibration”).
C
HANNEL
I
NDICATION
At any time, you can select any one of the 3000PLUS
instrument’s three separate output channels for display:
• Channel 1
—the meter’s basic ±5-VDC scaled out-
put, representing measured engineering units (after
calibration). It is produced solely for display and
interrogation via the
CHANNEL (CHN)
command
(described in Appendix A).
1.
D
D
ATA AND
S
TATUS
D
ISPLAYS
1
Under a reading of about 32000, the display’s least significant
digit will change by 1; from 32000 to 64000, it will change by 2;
and over 64000, by 5.
2
That is, the precision (decimal-point location) both of the basic
±5-volt scaled output (Channel No. 1) and of the “auxiliary” DAC
output (Channel No. 2) will always reflect that of the currently
stored FSU number—as will that of other setup values that
directly relate to the 3000PLUS’s scaled engineering-units read-
ing, including display offset, high/low limit and hysteresis val-
ues, “peak defeat” threshold, tared output value, and all
calibration numbers (both “absolute” and “two-point”) that are
expressed in units.
3
Since the display offset is automatically set to zero during
instrument calibration (either “absolute” or “two-point”), you
should set a nonzero DSO value only after calibration has been
performed (Sections 3 and 4).
4
The Configurator software’s “Live Output Window” (described
in Section 4.D), lets you view any selected channel and modify
applicable output characteristics on a run-time basis.
