BEKA BA374C, Руководство пользователя

Страница: 25 / 27

11.3 Description of programmable functions
The following sections contain detailed descrip-
tions of each programmable function. They should
be read in conjunction with the programme struc-
ture shown in Fig 13.
11.3.1 Alarm enable: EnbL
This function allows the alarm to be enabled or
disabled without altering any of the alarm
parameters. To check or change the function
select 'EnbL' from the alarm sub-menu and press
P
which will reveal the current setting. The function
can be changed by pressing the
Up or Down
button followed by the E button to return to the
'EnbL' prompt.
11.3.2 Setpoint adjustment: SP1 and SP2
The setpoint of each alarm relates to the
transmitter display and each may be independently
positioned anywhere in the transmitter display
range. When positioned close to the display limits,
care should be taken to ensure that hysteresis
does not place the alarm beyond the display limits.
To adjust the setpoint select 'SP1' or 'SP2' from
the alarm sub-menu and press
P which will reveal
the existing alarm setpoint. Each digit of the
setpoint can be adjusted using the
Up and Down
push-buttons, and the P button to move to the next
digit. When the required setpoint has been
entered press
E to return the setpoint prompt
'SP1' or 'SP2'.
11.3.3 Alarm function: HI.LO
Each alarm can be conditioned as a high or low
alarm. To check or change the alarm function
select 'HI.LO' from the alarm sub-menu and press
P to reveal the current setting. The function can
be changed by pressing the Up or Down buttons
followed by the E button to return the 'HI.LO'
prompt.
11.3.4 Alarm output status: no.nc
This function allows the alarm output to be open or
to be closed in the alarm condition. When
deciding which is required, care must be taken to
ensure that the alarm output is fail safe.
See Fig 13.
WARNING !
When the transmitter supply is
removed both alarm outputs will
open irrespective of conditioning.
Therefore for fail safe operation both
alarm outputs should be
programmed to be open in the alarm
condition.
To check or change the alarm output status select
'no.nc' from the alarm sub-menu and press
P
reveal the current setting. The function can be
changed by pressing the
Up or Down button
followed by the E button to return the 'no.nc''
prompt.
11.3.5 Hysteresis: HStr
To adjust the hysteresis select 'HStr' from the
alarm sub-menu and press
P which will reveal the
existing figure. Each digit can be adjusted using
the
Up and Down push-buttons, and the P button
to move to the next digit. When the required
hystersis has been entered press
E to return the
'HStr' prompt.
e.g. A transmitter with a high alarm set at 240 and
hysteresis of 10 will perform as follows:
High alarm will be activated when display
equals or exceeds 240, but will not reset until
the display falls below 230.
11.3.6 Alarm delay: dELA
This function enables activation of the alarm
output to be delayed for a fixed time following the
alarm condition occurring. The delay can be
programmed in 1 second increments up to 3600
seconds. If a delay is not required zero should be
entered. To adjust the delay select 'dELA' from the
alarm sub-menu and press
P which will reveal the
existing delay. Each digit of the delay can be
adjusted using the
Up and Down push-buttons, and
the P button to move to the next digit. When the
required delay has been entered press E to return
the 'dELA' prompt.
11.3.7 Alarm silence time: SIL
This function is primarily intended for use in small
installations where the alarm output directly
operates an annunciator such as a sounder. When
the alarm silence time is set to any figure other
than zero, the
P push-button becomes an alarm
accept button. After an alarm has occurred,
operating the
P button will cause the alarm output
to revert to the non-alarm condition for the
programmed alarm silence time. The display will
continue to indicate an alarm after it has been
accepted and silenced. The alarm silence time
may be adjusted between 0 and 3600 seconds in 1
second increments.
To adjust the alarm silence time select 'SIL' from
the alarm sub-menu and press
P which will reveal
the existing time. Each digit can be adjusted using
the
Up and Down push-buttons, and the P button
to move to the next digit. When the required time
has been entered press
E to return the 'SIL'
prompt.
25