10.3 Description of programmable functions
The following sections contain detailed descriptions
of each programmable function. They should be
read in conjunction with the alarm programme
structure shown in Fig 11.
10.3.1 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
may be changed by pressing the
Up
or
Down
button followed by the
E
button to return the 'EnbL'
prompt.
10.3.2 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
may 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'.
10.3.3 Alarm function: HI.LO
Each alarm may 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 may
be changed by pressing the
Up
or
Down
buttons
followed by the
E
button to return the 'HI.LO'
prompt.
10.3.4 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.
WARNING
When the transmitter power 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
to
reveal the current setting. The function may be
changed by pressing the
Up
or
Down
buttons
followed by the
E
button to return the 'no.nc'
prompt.
10.3.5 Hysteresis: HStr
To adjust the alarm 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.
10.3.6 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.
10.3.7 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 may 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.
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