01-06-2012, 03:57 PM
The Design of Tiered Pricing Meter Based on ZigBee Wireless Meter Reading
System
[attachment=23894]
INTRODUCTION
ZigBee wireless sensor network is a wireless data
transmission network based on IEEE 802.15.4 standard and
ZigBee network protocol [1]. This network is a short-range,
low-rate wireless sensor network and has low cost, low
power consumption, fast auto-configuration and autorecovery
of network in radio frequency transmission.
Zigbee wireless communication protocol consists of the
physical (PHY), medium access control (MAC), network
(NWK) and application layers.
ZIGBEE TECHNOLOGY STANDARD
IEEE 802.15.4 standard, finalized in May 2003, is a
low-speed Wireless Personal Area Network (PAN) standard
determined by IEEE and satisfies Open Systems
Interconnection (OSI) reference model of the International
Organization for Standardization (ISO). In comparison with
other wireless network, IEEE802.15.4 agreements have
outstanding advantages: good network capability, wide
adaptation, high reliability and high energy efficiency.
THE DESIGN OF METER SYSTEM SOFTWARE
A. Energy measurement program realization
After MSP430FE427 resets, the registers related to the
ESP modules needs initializing. Initialization of the ESP
module includes initialization of analog front-end register
and parameter registers (through the mail). Analog frontend
initialization consists of choosing clock source of AD
sampling and selecting following parameters: frequency
division factor of the clock, reference voltage, the gain of
pre-amplifier and the over-sampling rate. The work is
prepared for the commencement of AD samples.
Initialization of parameter register is to provide the ESP
with the calculating basis and compensation factor, which
typically includes:
EXPERIMENTS
During the experiment of the energy metering program
in MSP430FE427, the energy generated by the new second
is divided into 4000 equal parts, and total energy of every
part is cumulated by timing interrupt to conveniently
determine whether the total energy has reached the energy
value of a pulse output. The timing interval is 0.25ms. The
more the shares are, the energy generated by one second is
more accurate. The MSP430FE427 manual suggests that the
number of the parts should not be less than 2000 parts in
order to guarantee that the error is less than the national
standard. In the test experiments of the energy meter, the
values of standard meter and tiered pricing meter are
measured at the same time and the measurements are
compared to determine measurement error. The results
show that the error of active power by experimental
measure is less than ± 0.5%. As a RFD node of wireless
reading system, the meter designed can join the wireless
sensor network less than 2s.
System
[attachment=23894]
INTRODUCTION
ZigBee wireless sensor network is a wireless data
transmission network based on IEEE 802.15.4 standard and
ZigBee network protocol [1]. This network is a short-range,
low-rate wireless sensor network and has low cost, low
power consumption, fast auto-configuration and autorecovery
of network in radio frequency transmission.
Zigbee wireless communication protocol consists of the
physical (PHY), medium access control (MAC), network
(NWK) and application layers.
ZIGBEE TECHNOLOGY STANDARD
IEEE 802.15.4 standard, finalized in May 2003, is a
low-speed Wireless Personal Area Network (PAN) standard
determined by IEEE and satisfies Open Systems
Interconnection (OSI) reference model of the International
Organization for Standardization (ISO). In comparison with
other wireless network, IEEE802.15.4 agreements have
outstanding advantages: good network capability, wide
adaptation, high reliability and high energy efficiency.
THE DESIGN OF METER SYSTEM SOFTWARE
A. Energy measurement program realization
After MSP430FE427 resets, the registers related to the
ESP modules needs initializing. Initialization of the ESP
module includes initialization of analog front-end register
and parameter registers (through the mail). Analog frontend
initialization consists of choosing clock source of AD
sampling and selecting following parameters: frequency
division factor of the clock, reference voltage, the gain of
pre-amplifier and the over-sampling rate. The work is
prepared for the commencement of AD samples.
Initialization of parameter register is to provide the ESP
with the calculating basis and compensation factor, which
typically includes:
EXPERIMENTS
During the experiment of the energy metering program
in MSP430FE427, the energy generated by the new second
is divided into 4000 equal parts, and total energy of every
part is cumulated by timing interrupt to conveniently
determine whether the total energy has reached the energy
value of a pulse output. The timing interval is 0.25ms. The
more the shares are, the energy generated by one second is
more accurate. The MSP430FE427 manual suggests that the
number of the parts should not be less than 2000 parts in
order to guarantee that the error is less than the national
standard. In the test experiments of the energy meter, the
values of standard meter and tiered pricing meter are
measured at the same time and the measurements are
compared to determine measurement error. The results
show that the error of active power by experimental
measure is less than ± 0.5%. As a RFD node of wireless
reading system, the meter designed can join the wireless
sensor network less than 2s.