BEKA BA368C, Руководство пользователя

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Fig 2.5 Setpoint adjustment from the display
mode
To adjust an alarm setpoint, select 'SPx1' or 'SPx2'
and press
P which will reveal the current setting.
Each digit of the setpoint may be adjusted using
the
Up and Down push-buttons, and the P button
to move control to the next digit. When the
required setpoint has been entered, pressing
E will
return the display to the 'SPx1' or 'SPx2' prompt
from which the other setpoint may be selected, or
the instrument may be returned to the display
mode by pressing
E again.
Note: Direct access to the alarm and control
output setpoints is only available when the menu is
enabled - see section 2.6.10
2.7 OPTIONAL 4/20mA OUTPUT
The BA368C can be supplied with an optional
4/20mA output which may be programmed to
produce an analogue output proportional to the
whole or part of the total or rate display. See
section 1.9.5.1 for intrinsic safety details.
2.7.1 Programming and adjustment
The main counter programme menu is extended
as shown in Fig 2.6 to accommodate the 4/20mA
calibration functions.
The ‘4-20 OP’ programme function allows the
4/20mA output current to correspond to any
positive total or rate display. e.g. 4mA could
represent 0 counts and 20mA 5000 counts.
Note: Negative display numbers can not be
represented by the 4/20mA output.
To calibrate the 4/20mA output current, enter the
programme mode by operating the
P and E push-
buttons simultaneously. Using the Up or Down
push-button select the function ‘4-20 OP’ and
press
P which will result in the BA368C displaying
the first sub-menu function ‘4.000’. – See Fig 2.6.
Using the
Up or Down push-button select the ‘4-20
tYPE’ function which enables the 4/20mA output to
be controlled by the total or rate display. Press
P,
select the required source and then return to the
sub-menu by pressing the
E button.
The displayed values which correspond to 4mA
and 20mA output may now be defined. Using the
Up or Down push-button select the ‘4.000’ prompt
for the function which defines the display at which
the output current will be 4.000mA. Press
P to
reveal the existing setting with the most significant
digit flashing. The decimal point will be fixed in the
position already defined for the display by the ‘d.P’
function. The value of the flashing digit may be
changed by pressing the
Up or Down buttons.
When this digit is set as required, pressing P will
transfer control to the next digit.
When the required display has been entered,
press the
E button to return to the ‘4.000’ prompt.
To enter the display at which the output current will
be 20.000mA, press the
Up or Down button to
select the ’20.000’ prompt followed by P to reveal
the current setting, which may be changed in the
same way as the 4mA setting. When adjusted as
required, press
E three times to return to the
display mode via the ‘20.000’ and ‘4-20 OP’
prompts.
The 4/20mA output may be calibrated to increase
or decrease as the display increases, and most
instruments will produce a linear output between
3.5 and 22mA.