BEKA BA374C, Руководство пользователя, Страница: 23 / 27

TThe maximum equivalent capacitance and
inductance between each set of alarm terminals is:
Ceq = 20nF
Leq = 10µH
These figures must be subtracted from the
maximum permitted cable capacitance and
inductance specified by the system certificate of
the circuit connected to the alarm.
Fig 12 Typical application of alarms
11.1.3 Programming & adjustment
When an alarm card is added to a BA374C
transmitter the Programme Menu is extended as
shown in Fig 13. The additional functions 'ALr1',
'ALr2' and 'AcSP' appear between 'Cond' and
'COde' in the programme menu. For simplicity Fig
13 only shows the functions available on alarm 1,
but alarm 2 has identical facilities.
The alarms relate to the digital display and the
setpoints are shown in the same units as the
display.
The following table summaries each of the alarm
programme functions and includes a cross
reference to more detailed information. Again
only the functions on alarm 1 are listed, but alarm
2 has identical facilities.
11.2 Summary of programmable alarm
functions.
Display Summary of function
'EnbL' Alarm enable
Enables or disables the alarm function
without changing the alarm parameters.
See section 11.3.1
'SP1' Alarm setpoint 1
Adjusts the alarm setpoint. The alarm
is activated when the indicator display
equals the setpoint.
The setpoint can also be adjusted
directly from the operating mode.
See section 11.3.2
'HI.LO' Alarm function
Defines whether the alarm has a high
or low function
See section 11.3.3
'no.nc' Normally open or normally closed
output
Determines whether the single pole
alarm output is open or closed in the
alarm condition.
See section 11.3.4
'HStr' Hysteresis
Adjusts the alarm hysteresis.
See section 11.3.5
'dELA' Alarm delay time
Adjusts the delay between the display
equalling the setpoint and the alarm
output being activated.
See section 11.3.6
'SIL' Alarm silence time
Defines the time that the alarm output
remains in the non-alarm condition
following acceptance of an alarm.
See section 11.3.7
'AcSP' Access setpoint
Sub-menu which enables the function
allowing direct access to the alarm
setpoints from the operating mode, and
defines a separate security code.
See section 11.3.8
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