User Manual EM737
Document code: Fineco737-1-1.1 Revision2.003
Shanghai fangqiu electric CO.,LTD. Email:
8.4
Communication Function
With an infrared COM and a RS485 COM. Its physical layers are independent with each
other. One communication channel will not be affected by the other one. The meter can
realize data acquisition, broadcast time setting, read, program and manage through
hand-held terminals, data acquisition terminal, test equipments and computers.
Communication protocols fit Modbus RTU standard.
RS485 circuit and energy meter internal circuit can realize electrical
isolation and failure
protection of circuit.
RS485 communications transfer rates allow selected at 1200bps, 2400bps, 4800 bps and
9600bps, default is 9600bps.The max quantity of meters on one RS485 main bus is 64 Units,
the longest communication distance is 1.2Km.
Note:
1. Use shielded twisted pair
2.
Connect 120Ω resistances with communication equipment and Energy meters to
preventing signal reflection and interference.
3.
Communication circuit should keep distance with Large current circuit and shall not be
parallel with it.
8.5
Alarm function
When the meter connect wire wrong example: current reverse, lost phase and reversed
phase sequence , the meter will display , the ALARM led will be on.
8.6
Pulse output function
Smart meter
is equipped with a pulse output which is fully separated from the inside
circuit. That generates pulses in proportion to the measured energy .include the testing
pulse output of active energy and reactive energy. 8/ 11 Test pulse output contact (P+/P-)
，
9/ 11 Test pulse output contact (Q+/Q-)
The test pulse output is a polarity defendant, passive transistor output requiring an
external voltage source for correct operation. For this external voltage source, the voltage
(Ui) should be 5-27V DC, and the maximum input current (Imax) should be 27mA DC. To
connect the impulse output, connect 5-27V DC to connector 8&9 (anode), and the signal
wire (S) to connector 11 (cathode). The meter pulses is indicated on the front panel.
