11
5. OPERATION AS A TIMER
When configured as a Timer the BA578E can
measure and display the elapsed time between
external events.
The Timer can be started and
stopped by remote sensors, or from the front panel
push buttons.
The addition of optional factory fitted isolated control
outputs allows the Timer to control external events
such as opening a valve for a predetermined time.
Again the Timer can be started and stopped by
remote sensors, or from the front panel push
buttons.
Timed events can be repeated using the
CYCLE
function which enables the BA578E Timer to
repeat the timing period up to 99 times, or
continuously, with a configurable delay between
timed periods of up to 100 hours.
The BA578E may be configured to time-up from
zero to the set time
5Et t
, or to time-down from the
set time to zero.
Times may be entered and
displayed in hours, minutes or in seconds, or in a
combination of units. Elapsed or remaining time is
continuously displayed and a separate display may
be activated to show the target set time
5Et t
.
Throughout the timing cycle the instrument can be
paused and restarted without changing the cycle
time. Resetting is accomplished via the front panel
push buttons or a remote contact.
A grand total time is maintained by the instrument
which can be viewed by operating the front panel
push buttons and reset from the display mode or
from within the configuration menu.
Fig 8 shows a simplified block diagram of the
BA578E when configured as a Timer.
The two
separate inputs A and b can be individually
configured to accept inputs from a wide variety of
sensors.
When the sensor requires energising to
detect its state, such as a switch contact, open
collector or a two wire proximity detector, a link
connected between external terminals of the
BA578E supplies power to the sensor input
terminals.
The optically isolated open collector status output is
intended for monitoring the Timer's status, but may
also be used for simple control applications.
The instrument can be supplied with the following
factory fitted accessories:
Internally powered Backlight
Dual isolated Control Outputs
The optional factory fitted dual isolated solid state
control outputs may be independently configured to
be activated in any of the timer's state allowing the
BA578E Timer to perform a wide variety of tasks.
5.1
Initialisation
Each time power is applied to a BA578E
initialisation is performed. After a short delay the
following display sequence occurs:
All segments of the display are activated
BA578E is ready to start functioning using
the configuration information stored in the
instrument's permanent memory.
Fig 8
BA578E block diagram with Timer
configuration.
