Page 55
Sonic-Pro
Industries, Ltd.
Industries, Ltd.
ProSeries
by Blue-White Ind.
TM
7.5.2
Digital
Pulse
Output
The digital pulse output has a frequency range of 0 to 1000 Hz. The correspondence of
pulse frequency to flow rate can be configured by specifying two (flow rate, frequency)
points. Low and high flow rates, which must not be the same, are specified and the
frequencies corresponding to each are given. Other flow rates are mapped to pulse
frequencies using a straight line through the points specified. The frequency for the high
flow rate may be smaller than the frequency for the low flow rate, in which case the
frequency will decrease with increasing flow rate. Flow rates mapping to frequencies
outside the available range will cause the signal to saturate at the closest limit.
The flowmeter is able to log flow data internally (to a removable SD Card) and, if the
Communication Board is fitted, to a connected User PC. The generation of a log entry can
be triggered periodically, by the flow rate passing configurable setpoints and by the total
flow passing configurable setpoints. All log entries are identical and do not indicate
which of the forgoing mechanisms caused their generation. All log entries look like this:
2006/12/15 13:10:43 Rate: 2396.25 Total: 4345625.38
The date is ordered year/month/day. The time is military or European time, so no
a.m./p.m. field is needed. The flow rate and total flow are recorded as they would appear
on the display. Units of measure are not included. A 32 Mbyte SD card (included) will
accommodate about 500,000 entries. At one entry per minute, it will fill up in a little less
than a year. If the SD Card is not present, data logging still takes place but only buffered
entries can be retrieved by a User PC Software application, see section 7.6.5 below.
The interval between periodic log entries can be configured from 1 to 999999 seconds. If
this number is set to zero, periodic logging will not occur. Log entries can only be
generated when flow information is produced for display.
Maximum and Minimum Flow Rate Setpoints can be configured in
Setup Mode
so that
the flowmeter records the time at which the flow rate crosses these values. A log entry is
generated when the flow rate crosses the
Maximum Flow Rate Setpoint
value while
increasing. A log entry is also generated when the flow rate crosses the
Minimum Flow
Rate Setpoint
value while decreasing. These log entries are not distinguished from
other entries and consist, as always, of the timestamp, the flow rate immediately after
the setpoint was crossed and also the total flow at that time.
When a log entry has been generated due to the crossing of a
Log Rate Setpoint
, as
described here, no further log entries are generated due to the crossing of the same
Log
Rate Setpoint
for a period of one minute. The intent is to suppress “flicker”, i.e. many
log entries due to the flow rate hovering around the setpoint and crossing it repeatedly.
Log Rate Setpoints
must be specified in the units of measure configured for flow rate.
Five
Flow Total Setpoint
values can be configured in
Setup Mode
so that the
flowmeter records the time at which the total flow crosses each of these values. When
this occurs, a single log entry is generated. It is not distinguished from other entries and
consists, as always, of the timestamp, flow rate and the actual total flow value that
exceeded the setpoint.
Flow Total Setpoint
values do not have to be in ascending order.
They must be specified in the units of measure configured for flow total.
7.6
Data
Logging
7.6.1
Periodic
Logging
7.6.2
Logging
Rate
Setpoints
7.6.3
Logging
Totalizer
Setpoints
