25
The maximum equivalent capacitance and
inductance of each BA334D alarm output is:
C
= 40nF
L
= 30µH
To determine the maximum permissible cable
parameters, the equivalent alarm output
parameters must be subtracted from the
maximum cable capacitance and inductance
specified by the system certificate of the circuit
connected to each alarm.
Fig 12 Typical alarm application
9.2.3 Programming and adjustment
When a BA334D is supplied with alarms the
main programme menu is extended as shown
in Fig 13. The two alarm functions appear
between the 'LOC-rSEt' and the 'CLr.Gtot'
functions, and each alarm may be programmed
as a rate or a total alarm.
For simplicity Fig 13 only shows the
programmable functions on the rate option of
alarm AL1. Alarm 2 and the total options are
identical except that the total alarms do not
have hysteresis.
The following table summarises each of the
alarm programme functions and includes a
cross reference to more detailed information.
Again only the functions on alarm AL1 are
listed.
Summary of programmable alarm functions
Display Description of function
'EnbL'
Alarm enable
Enables or disables the alarm
function without changing the alarm
parameters.
See section 9.2.4
'tYPE'
Type of alarm
Defines whether the alarm operates
on the rate or total display.
See section 9.2.5
'SPr1'
Alarm setpoint 1
or
Adjusts the alarm setpoint. The
‘SPt1’
alarm is activated when the rate or
total display equals the setpoint.
Note:
‘SPr1’ is displayed for a rate
alarm and ‘SPt1’ for a total alarm.
See section 9.2.6
'HI.LO'
Alarm function
Defines whether the alarm has a
high or low function
See section 9.2.7
'no.nc'
Normally open or normally
closed output
Determines whether the single pole
alarm output is open or closed in
the non-alarm condition.
See section 9.2.8
'HStr'
Hysteresis
Adjusts the alarm hysteresis. Only
available on rate alarms.
See section 9.2.9
'dELA'
Alarm delay
time
Adjusts the delay between the
display equalling the setpoint and
the alarm output being activated.
See section 9.2.10
'SIL'
Alarm silence time
Defines the time that the alarm
output remains in the non-alarm
condition following acceptance of
an alarm.
See section 9.2.11
'AcSP'
Access setpoint
Sub-menu that enables direct
access to the alarm setpoints from
the display mode and defines a
separate security code.
See section 9.2.12
Summary of Contents for BA334D
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