1. Measurement function
a) It has the function of measuring forward active energy and reverse active energy and storing its data. Forward and reverse energy are respectively measured. By default, the combined active energy is the absolute sum of positive and negative energy.
b) With time-sharing metering function, the active power energy accumulates and stores total, peak, peak, flat and valley power energy according to the corresponding time period.
2. Timing function
a) The built-in hardware clock circuit with temperature compensation function is adopted, and the output frequency of the internal clock terminal is 1Hz.
b) The clock has the function of calendar, timing and leap year automatic conversion.
c) Use environmentally friendly lithium batteries as backup power for the clock; The clock backup power supply does not need to be replaced within the life cycle of the energy meter, and can maintain the correct working time of the internal clock for no less than 5 years after power failure; When the battery voltage is insufficient, the watt-hour meter gives an alarm.
d) When the watt-hour meter is calibrated through communication interfaces such as RS485 and infrared, the date and time are set with security measures to prevent unauthorized operation. Except for broadcast calibration, the calibration must be performed in ciphertext.
e) The watt-hour meter will only accept broadcast time correction with clock error of not more than 5 minutes; It is allowed to be corrected once a day (if the date changes, it is allowed to be corrected), and it should be avoided within 5 minutes before and after the energy meter performs the settlement data transfer operation.
f) In the temperature range of -25 ~ +60℃, clock accuracy ≤±1.0s/d; At the reference temperature (23℃), the clock accuracy is ≤±0.5s/d.
3, rate, time
a) Support four rates: peak, peak, flat and valley.
b) There are two sets of rates and periods that can be programmed arbitrarily, and another set of rates and periods can be started at a set time point.
c) Each rate period can be set at least 2 time zones throughout the year; At least 8 periods can be set within 24 hours; The minimum interval is 15 minutes. Time periods can cross the zero setting.
d) Support the setting of special rate periods on public holidays and weekdays.
4. Clear the meter
a) Clear the electrical energy, frozen amount, event record, load record and other data stored in the energy meter.
b) Clear operation as a permanent record of the event, with security measures to prevent unauthorized persons from operating.
c) The energy meter bottom value can only be cleared to zero, can not be set.
5. Data storage
a) Can store unidirectional or bidirectional total power and each rate power data for 12 billing days.
b) The settlement time is missed when the power failure, and 12 settlement energy data can be completed when the power is powered on.
c) In the event of power failure of the meter, all data related to the settlement shall be kept for at least 10 years, and other data shall be kept for at least 3 years.
6. Freezing function
a) Timing freezing: freezing electrical energy data at the agreed time and interval; Store each frozen quantity at least 60 times.
b) Instantaneous freezing: freezing the current calendar, time, all electrical energy and important measurement data under abnormal conditions; Instantaneous freezing saves the data of the last 3 times.
c) Agreed freezing: when the new and old two sets of rate/time conversion, ladder electricity price conversion or the power company considers that there is a special need, freeze the electricity energy at the conversion time and other important data.
d) Daily freezing: storage of electrical energy at 00:00 every day, can store 62 days of data. The daily freezing time is missed when the power is off. The frozen data of the whole day is replenished when the power is on. The frozen data of the last 7 days is replenished at most.
e) Freezing at the hour: Store the total active power at the hour or half hour, and can store 254 data.
f) The frozen content and corresponding data identification shall comply with DL/T 698.45 and its filing requirements.
7. Event record
a) Permanently record the time when the energy meter is cleared and the electricity energy data when it is cleared.
b) Record the total number of programming times, the time of the last 10 programming times, the operator code, and the data identification of programming items.
c) Record the total number of times of calibration (excluding broadcast calibration), the time of the last 10 calibration times, and the operator code.
d) Record the total number of power failures, and the last 10 power failures occurred and ended.
e) Record the last 10 times of pulling and closing events, record the time of pulling and closing events, operator code and electrical energy and other data.
f) Record the total number of meter cover opening, the occurrence and end time of the last 10 meter cover opening events and the electricity energy data at the time of meter cover opening. During the power outage, the energy meter only records the earliest meter cover opening event.
8. Communication function
8.1 485 Communication
a) The RS485 interface and the internal circuit of the energy meter are electrically isolated, and there is a fail-safe circuit.
b) RS485 interface meets DL/T 698.45 electrical requirements, and can withstand AC voltage 380V, 2 minutes without damage test.
c) The communication rate of the RS485 interface can be set. The standard rate is 1200bps, 2400bps, 4800bps, and 9600bps. The default rate is 9600bps.
d) RS485 interface communication follows the DL/T 698.45 protocol and its documentation.
e) The energy meter can communicate with the RS485 port within 3s after being powered on.
f) The RS485 interface can ensure normal communication between the forward and reverse wires on the 485 bus.
8.2 Infrared Communication
a) With modulated or contact infrared interface.
b) The electrical and mechanical properties of the infrared interface shall meet the requirements of DL/T 698.45.
c) Effective infrared communication distance ≥5 meters.
d) The default communication rate of the modulated infrared interface is 1200bps.
e) Infrared communication follows the DL/T 698.45 protocol and its documentation.
f) Before performing infrared operations, perform infrared authentication and enable operation permissions.
8.3 Carrier Communication
a) The energy meter can be configured with narrowband or broadband carrier module.
b) The communication between the energy meter and the carrier mode communication block follows the DL/T 698.45 protocol and its filing documents.
c) The default interface communication rate is 9600bps.
d) An external plug and play carrier communication module is adopted, and the carrier communication interface has a fail-safe circuit.
e) During carrier communication, the metering performance, stored metering data and parameters of the energy meter will not be affected or changed.
f) The energy meter can carry out carrier communication within 5 seconds after power-on.
8.4 Micro Power Wireless Communication
a) The communication between the watt-hour meter and the micro-power communication module follows the DL/T 698.45 protocol and its documentation.
b) The default interface communication rate is 9600bps.
c) External plug-and-play micro-power communication module is adopted, and the micro-power communication interface has a fail-safe circuit.
d) During micro-power communication, the metering performance, stored metering data and parameters of the watt-hour meter are not affected or changed.
9. Signal output
9.1 Electrical energy pulse output
a) There should be an optical pulse output and an electrical pulse output proportional to the measured electrical energy (active/reactive).
b) The light pulse output adopts ultra-bright and long-life LED devices.
c) The electrical pulse output should be electrically isolated and can be collected from the front.
9.2 Multi-function signal output
a) Multi-function signal output terminal can output time signal or time switching signal; Two kinds of signals are set and converted by software; After the energy meter is powered on for the first time, or powered on again after power failure, the multi-function signal output is initialized to the time signal output.
b) The time signal is the second signal; Time slot switching signal is pulse signal.
c) The time slot switch signal is sent when the time slot changes, and the time slot switch signal is still output even if the rate is unchanged.
5.9.3 Control Output
The energy meter can output electrical pulse or level switch signal (output mode can be set) to control external alarm device or load switch.
10. Display function
a) The LCD starts the backlight when the watt-hour meter is operated in normal working state, such as pressing buttons and infrared communication. After the backlight is started by pressing the button or the card, the backlight is automatically turned off without operation for 60 seconds. When infrared is triggered, the backlight is turned off after 2 automatic wheeling cycles.
b) The energy meter display content is divided into three kinds: numerical value, code and symbol; The display content can be set programmatically.
c) The energy meter has the function of wake up display after power failure.
d) With automatic cycle and key two display modes; The automatic cycle display interval can be set within 5 to 20 seconds.
e) With the power on full display function, the energy meter in 1 second after the power on the LCD full screen display, LED lights are fully lit (except pulse lights); The default time for the LCD and LED to turn on and turn on the backlight is 5s, and the interval can be set within 5 to 30s.
f) With the function of full display of live energy meter LCD screen and full brightness of LED lamp through communication command (except pulse lamp), the maintenance time of LCD display and LED light is 10s.
g) The energy meter can test the state of key and official key through the liquid crystal display.
11. Cost control function
a) Electricity meter billing through the carrier, 485 or wireless and remote power sale system to achieve charge control, the user's electricity is stored in the main station, the electricity meter is only a measuring instrument and control of the executive mechanism.
b) The power meter realizes the charge control function through remote commands, including: tripping, closing permit, alarm, alarm release, power retention, power retention release. When the main station detects that the user's remaining electricity is insufficient, it sends an alarm command to remind the user to pay money to buy electricity as soon as possible; When the remaining electricity cost of the user is finished, the main station issues a trip command to remind the user to buy electricity; When there are special circumstances that can not be powered off (such as the Spring Festival, etc.), the main station can issue a power preservation command in advance to ensure that the energy meter will not trip under any circumstances.