Data Logger for Water Meter
Function
Continuously counts pulses from pulse output of the water meter (or other meters with pulse output)
and periodically records non-zero values to internal nonvolatile memory for further data transfer to PC.
Features
• Input Pulse frequency up to 20Hz with digital
filtering for debouncing cancelation
•
Isolated input for Reed Switch or Voltage
Pulse
•
Selectable Recording Period (beginning from
1s with 1s step)
• Nonvolatile memory for data storage:
a) FRAM (2Mbit for 37400 records)
b) microSD card optionally (up to 2Gbit)
• Interface with PC for remote data reading:
a) Isolated RS-485 interface with selectable
Baud Rate up to 460800 baud/s
b) Optional GSM/GPRS communication (TCP/IP)
•
Data archiving and visualization on the PC
•
+5…12VDC power supply
•
Package for DIN rail mounting
•
Operating temperature range -25…+75℃
Data Logger connection to Meter and PC
RS-485
• Bus length up to 1 km
• Selectable baud rate up to 460800 baud/s
• Virtual COM port
GSM/GPRS
• No wires, no distance limitation
• Onboard SIM card with connection to
mobile Internet
• TCP/IP communication protocol
Block diagram of the Data Logger
Input Circuit
Digital anti debouncing filtering algorithm is
implemented in MCU program.
Minimal pulse width is limited at 25ms, that
allows pulse rate up to 20Hz.
Pulse Input accepts Reed Switch and Voltage
Pulses (up to 36V). See figures on the left for
more info.
Input Circuit protection against reverse
polarity of the signal.
+5V
+5V
GND
GND
MCU Pulse In
IN+
Pulse
INGND
Operation principles
Recording Period is designated as T on the time diagram above. When this interval
expires, non-zero value of the Pulse Counter with time stamp (seconds, minutes, hours,
days, weekdays, months, years) are written to the nonvolatile memory. Then Pulse
Counter is cleared to start counting pulses for the next recording period.
Recording period selectable from 1s with 1s step.
20-bit Pulse Counter is used for counting pulses.
PC software. Setup and configuration.
Main window
Configuration of the
virtual COM port
Setting and reading
parameters
Data visualization. Table and chart formats.
Data Logger records
In March
Daily water
consumption in March
Data archiving
on the PC
Data export to Excel
Detailed data representation
for short time interval
The same data, but current
value is added to the sum of
previous values. The last
value is equal to total water
consumption for selected
time interval.