Unlike the
CAL
function, an accurate external current
measuring instrument is not required and the Set
Point Station does not have to be disconnected from
the loop, however calibration can only be performed
at 4mA and 20mA. Although not traceable to a calib-
rated standard, accuracy is adequate for many in-
dustrial applications.
To calibrate the Set Point Station’s digital display se-
lect
5Et
from the configuration menu and press
(
.
The Set Point Station will display
4
.
000
, pressing
(
again will reveal the calibrated display at 4mA
output with one digit flashing. The flashing digit may
be adjusted by pressing the
&
or
*
buttons, when
the flashing digit is correct pressing
(
will transfer
control to the next digit. When all the digits have
been adjusted, press
)
to return to the
4
.
000
prompt.
Calibration of the Set Point Station display at 20mA
output is performed in exactly the same way using
the
20
.
000
sub-menu which may be selected from
the
4
.
000
prompt using the
&
or
*
button.
When
the display corresponding to a 20mA output has
been entered pressing
)
twice will enter the setting
and return to the
5Et
prompt in the configuration
menu.
The bargraph is not displayed while using the
5Et
function
To obtain a reverse acting display i.e. the Set Point
Station display decreases as the output current in-
creases, the required display value entered into
4
.
000
should be greater than that entered into
20 . 000
. The
&
or
*
buttons on the front of the in-
strument always indicate which way the display will
change when the button is pushed.
The bargraph will start at the numerical display
entered for 4mA output and finish at the numerical
display entered for 20mA output, except for reverse
acting calibration when it will also be reversed.
5.6
High & low current output limits:
H--L
The BA627E-SS output is normally adjustable
between 3 and 22mA, but may be restricted by this
function if a limited adjustment range is required.
e.g. to prevent a dangerously high and/or low tem-
perature being selected when used as the set point
input for a temperature controller.
When the Set
Point Station’s output current equals the high limit,
oVEr
is displayed, similarly
undEr
is displayed when
the output current equals the low limit.
To restrict the Set Point Station’s output current
range select
H--L
from the configuration menu and
press
(
. Using the
&
or
*
button select
Lo
to
adjust the lower current output limit, or
Hi
to adjust
upper output current limit. Pressing
)
will display
the selected output current limit in milliamps with one
digit flashing.
The flashing digit may be adjusted by pressing the
&
or
*
button, when the flashing digit is correct
pressing
(
will transfer control to the next digit.
When all the digits have been adjusted press
)
t
o
return to the
Lo
or
Hi
prompt followed by
)
to enter
the adjustments and return to the
H--L
prompt in the
configuration menu.
Notes:
a. The
Lo
limit can not be adjusted to a value
above the present Set Point Station output cur-
rent, and the
Hi
limit can not be adjusted to a
value below the present Set Point Station output
current.
The actual Set Point Station output
current should therefore be adjusted to within
the acceptable output range before the
Lo
and
Hi
limits are adjusted.
b. If any of the five pre-set output currents are set
below the
Lo
limit or above the
Hi
limit, they will
not be selectable and
oVEr
or
undEr
will be dis-
played.
5.7
Pre-set outputs:
P5Et
Up to five pre-set current outputs may be stored and
recalled from the front panel push buttons which en-
ables common output currents to be quickly selec-
ted.
e.g. frequently used operating temperatures
when a BA627E-SS is used as the set point input for
a temperature controller.
To enter pre-set values select
P5Et
from the config-
uration menu and press
(
which will result in
5Et 1
, the first pre-set sub-menu being displayed,
pressing
(
will then reveal the present value in en-
gineering units with one digit flashing. The flashing
digit may be adjusted by pressing the
&
or
*
but-
ton, when the flashing digit is correct pressing
(
will
transfer control to the next digit. When all the digits
have been adjusted, press
)
to return to the
5Et 1
prompt from which any of the other four pre-sets
may be selected via the
&
or
*
button and adjus-
ted in the same way as
5Et 1
.
Notes:
a.
P5et
only appears in the configuration menu
when
P5Et
is selected in the
P
.
Fn
menu which
defines the function of the
(
push button in
the operating mode. see section
5.9.
b.
Maximum adjustment resolution is always
available for inputting pre-set values and is
used to determine the current output when the
pre-set is selected, irrespective of the adjust-
ment resolution selected in function
rE5n
- see
5.2
c.
If, after calibration of the Set Point Station dis-
play, previously entered pre-set values are out-
side the revised output current range, when se-
lected the pre-set value alternating with
oVEr
or
undEr
will be displayed.
13
Summary of Contents for BA627E-SS
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