3
1. DESCRIPTION
The BA538C is an externally powered pulse input
rate totaliser primarily intended for use with
flowmeters. The instrument simultaneously
displays the rate of flow and the total flow in
engineering units on two separate displays.
Housed in a robust 72 x 144 panel mounting DIN
enclosure, the BA538C has an IP65 front panel
and is supplied with a gasket to seal the joint
between the instrument and the panel.
2. OPERATION
Fig 1 shows a simplified block diagram of a
BA538C. The instrument accepts pulses from a
single source and after scaling displays the total
number of pulses received and their rate on
separate displays. When connected to a pulse
output flowmeter the BA538C will provide an
accurate display of total flow and the rate of flow.
The BA538C has two sets of input terminals for
connection to high or low level voltage pulses, a
switch contact, an open collector output or to a
two wire proximity detector. The instrument may
therefore be used with almost any pulse output
flowmeter. The total display may be reset to
zero by a remote switch contact or from the front
push-buttons.
Optional accessories enable the flow rate to be
transmitted to other equipment as an isolated
4/20mA analogue signal and the total flow to be
transmitted as a pulse signal. Optional alarms,
which may be programmed to function on the rate
or total displays, further extend the instrument’s
applications.
Fig 1 Simplified block diagram of BA538C
2.1 Initialisation
Each time power is applied to the instrument
initialisation is performed. After a short delay the
following display sequence occurs:
All segments of the display are activated for
about 2 seconds.
The product firmware number and the
version number are displayed for about 2
seconds.
Rate display and totaliser start to
function
using calibration information
stored in the instrument's permanent
memory.
2.2 Controls
The BA538C is controlled and calibrated via four
front panel push-button switches. In the display
mode i.e. when the instrument is displaying rate
and total flow the switch functions are:
Description of Switch Functions
E+ Down
While these buttons are pushed the
total display will show the least
significant eight digits of the grand
total, and the grand total annunciator
will be activated.
E
+
Up
While these two buttons are pushed
the total display will show the most
significant eight digits of the grand total
and the grand total annunciator will be
activated.
Down
Resets the total display to zero
+Up
when these two push-buttons are
operated simultaneously for more than
two seconds.
Selectable function from programme
menu.
See section 5.12
Down
While these buttons are pushed the
+P
instrument will display the firmware
part number and version number
.
Note
: When optional alarms are fitted the push-
buttons may be programmed to have alternative
functions – see section 8.3
Summary of Contents for BA538C
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