5.8
Maximum output rate of change:
rAtE
To minimise plant disturbance when the Set Point
Station output current is adjusted, the maximum rate
of change is defined by this function. The maximum
rate is adjustable between approximately 1 and 100
seconds for full scale output travel from 4 to 20mA.
If 0 seconds is selected the function is disabled.
To define the maximum rate of change of the Set
Point Station output select
rAtE
from the configura-
tion menu and press
(
which will reveal the present
maximum rate of change in seconds with one digit
flashing.
The flashing digit may be adjusted by
pressing the
&
or
*
buttons, when the flashing di-
git is correct pressing
(
will transfer control to the
next digit. When all the digits have been adjusted,
press
)
to enter the new value and return to the
configuration menu.
When the output rate of change limitation is function-
ing, in the operating mode the Set Point Station di-
gital display will show the requested output and will
flash until the requested output current is achieved.
The bargraph display always shows the Set Point
Station’s actual output.
Pressing the
)
button while the output is ramping to
a new requested value will stop the output changing.
5.9
Function of the
(
push button in
operating mode:
P
.
Fn
Using this function the Set Point Station may be con-
figured to display the output current in milliamps, the
output current as a percentage of the output range,
or to provide access to the five pre-set outputs when
the
(
button is pressed in the operating mode.
To check or change the function of the
(
push but-
ton select
P
.
Fn
from the configuration menu and
press
(
to reveal the present setting. Pressing the
&
or
*
button will scroll the setting between:
PC
Output as a percentage of output
range.
4-20
Output current in milliamps
P5Et
Access to the five pre-set outputs
see 5.7
When set as required, press
)
to return to the
P
.
Fn
prompt in the configuration menu.
5.10
Encoder: EnC
For applications requiring the Set Point Station’s
4/20mA output current to be controlled by a rotary
knob, an external three wire quadrature encoder may
be directly connected to terminals 5, 6 and 7.
The BEKA BA490 Is a panel mounting encoder that
generates 12 contact pulses per revolution which
complies with the requirements for
simple apparatus
and is intended for use with the BA627E-SS. Other
encoders that produce a different number of contact
pulses per revolution may also be used. So that all
external encoders have a similar adjustment resolu-
tion, the
EnC
function enables the number of pulses
between 6 and 48 per revolution to be defined.
To enter the number of pulses per revolution that the
external encoder generates, select
EnC
from the con-
figuration menu and press
(
which will reveal the
existing setting 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 other digit. When both digits
have been adjusted press
)
to return to the
EnC
prompt in the configuration menu.
Section 7.4 contains information about the use of an
external rotary encoder.
5.11
One or two handed operation:
Hnd
This function defines whether the front panel
)
but-
ton has to be pushed at the same time that the
&
or
*
button is operated, or the optional external
encoder is rotated to adjust the Set Point Station's
output current.
Selecting the two handed operation
which requires the
)
button to be operated which
minimises the possibility of accidental adjustment.
To check or change the function select
Hnd
from the
configuration menu and press
(
to reveal the exist-
ing setting. Pressing the
&
or
*
button will toggle
between the two setting:
2 H
Output current can only be adjusted
when the
)
button is pressed.
1 H
Output current can be adjusted
without pressing the
)
button.
When set as required, press
)
to return to the
Hnd
prompt in the configuration menu.
5.12
Security code:
CodE
Access to the instrument configuration menu may be
protected by a four digit security code which must be
entered to gain access.
New instruments are con-
figured with the default security code
0000
which al-
lows unrestricted access to all configuration func-
tions.
To enter a new security code select
CodE
from the
configuration menu and press
(
which will cause
the Set Point Station to display the existing security
code with one digit flashing. The flashing digit can
be adjusted using the
&
and
*
push buttons,
when set as required operating the
(
button will
transfer control to the next digit.
14
Summary of Contents for BA627E-SS
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