Panasonic KW8M - Pulse Output (Transistor Output) Specifications; Communication Specifications

KW8M Eco-POWER METER
71
9.3 Pulse output (Transistor output) Specifications
Number of output point 1 point
Insulation method Optical coupler
Output type Open collector
Output capacity 100mA 30V DC
Pulse width approx. 100ms
ON state voltage drop 1.5V or less
OFF state leakage current
100μA or less
Pulse output unit
0.001/0.01/0.1/1/10/100kWh/Alarm(AL-P)/
Current alarm(AL-C) /Stand-by alarm (AL-S) /Counter(Cnt)/
Demand alarm(DEM)* (Selectable with setting mode)
*Demand alarm is only for AKW8111H
* We recommend the setting of minimum unit for pulse output for measurement shown as below.
Output pulse: 4 pulses or less per 1sec.
How to calculate
(Unit for pulse output：PL-P)＞(Max. measurement power [kW])／(3600[s]×4 [pulse/s])
Caution (1) Improper unit setting may cause miss counting.
(2) If the OFF time is too short, there is a possibility of counting errors.
*Contact output status can be checked via RS485.
9.4 Communication Specifications
Interface Conforming to RS485
Protocol MEWTOCOL/MODBUS(RTU) (selectable with setting mode)
Isolation status Isolated with the internal circuit
Number of connected units 99 (max.) *
2 *3
Transmission distance 1200m (max.)
*1
Transmission speed 38400/19200/9600/4800/2400bps (selectable with setting mode)
Transmission
Format
Data length
8bit/7bit (selectable with setting mode) *
4
Parity Not available / Odd number / Even number (selectable with setting mode)
Stop bit
1bit（fixed）
Communication method
Half-duplex (When using as a terminal, short E and －.)
Synchronous system Synchronous communication method
Ending resistance approx. 120Ω(built-in)
Transmission line Twisted-pair cable with shield or VCTF
Communication mode 1 : N communication
*1 Please check with the actual devices when some commercial devices with RS485 interface are
connected. The number of connected devices, transmission distance, and transmission speed may
be different according to using transmission line.
*2 For RS485 converter on the computer side, we recommend SI-35 and SI-35USB (from LINE EYE
Co.,Ltd.).
*3 When using SI-35, SI-35USB or PLC from our company (which can be connected up to 99 units),
up to 99 Eco-POWER METER can be connected. In case using this system with the other devices,
up to 31 Eco-POWER METER can be connected.
*4 With MODBUS (RTU) protocol, it works only with 8bit.