START
115200, baud rate, from 1200,2400 ~ 57600,115200
N, N=No Parity, E=EVEN, O=ODD
1, 1=one STOP bit, 2=two STOP bits
100, TimeOut for Modbus command, format=Dec, valid=[0 ~ 255], unit=0.01 sec, 0.01x100=1 sec, max=2.55 sec
0, delay in the end of Modbus command, format=Dec, valid=[0 ~ 255], unit=0.01 sec, max=2.55 sec
0, InTxPdoMax/2, format=Dec, valid=[0 ~ 128], default=0=Auto
0, OutRxPdoMax/2, format=Dec, valid=[0 ~ 128], default=0=Auto
0 2 0 0 0 0 0, 7 Reserved, format=Hex, default=0, Ctrl[1]=2:display_value=read_value * 100.0
19, 19 commands(00-18), max=300, format=Dec
04 04 11 00 00 12, 01, 00, 20, InTxPdo[01..09]=V_a to KVAh_a, IEEE 754, update cyclically, (00)
04 04 11 48 00 02, 0A, 00, 20, InTxPdo[0A]=Freq_a, IEEE 754, update cyclically, (01)
04 04 11 12 00 12, 0B, 00, 20, InTxPdo[0B..13]=V_b to KVAh_b, IEEE 754, update cyclically, (02)
04 04 11 4A 00 02, 14, 00, 20, InTxPdo[14]=Freq_b, IEEE 754, update cyclically, (03)
04 04 11 24 00 12, 15, 00, 20, InTxPdo[15..1D]=V_c to KVAh_c IEEE 754, update cyclically, (04)
04 04 11 4C 00 02, 1E, 00, 20, InTxPdo[1E]=Freq_c, IEEE 754, update cyclically, (05)
04 04 11 36 00 12, 1F, 00, 20, InTxPdo[1F..27]=V_avg to KVAh_tot, IEEE 754, update cyclically, (06)
04 04 11 4E 00 02, 28, 00, 20, InTxPdo[28]=Freq_max, IEEE 754, update cyclically, (07)

04 04 02 00 00 01, 29, 00, 00, InTxPdo[29]=wiring, update cyclically, (08)
04 04 02 01 00 01, 2A, 00, 00, InTxPdo[2A]=phase, update cyclically, (09)
04 04 02 02 00 01, 2B, 00, 00, InTxPdo[2B]=name, update cyclically, (10)
04 04 02 03 00 01, 2C, 00, 00, InTxPdo[2C]=type, update cyclically, (11)
04 04 02 04 00 01, 2D, 00, 00, InTxPdo[2D]=ver, update cyclically, (12)

04 0F 10 00 00 02 01 00, 1, 00, 00, D/O_0/1=OutTxPdo[1].bit0/bit1, update cyclically, (13)
04 01 10 00 00 02, 2E, 00, 00, InRxPdo[2E].bit0/bit1=D/O_0/1, update cyclically, (14)

04 03 10 03 00 01, 2F, 00, 00, InTxPdo[2F]=PT_ratio, update cyclically, (15)
04 03 10 04 00 01, 30, 00, 00, InTxPdo[30]=CT_ratio, update cyclically, (16)
04 06 10 03 00 00, 02, 00, 08, PT_ratio=OutRxPdo[2], state change update(17)
04 06 10 04 00 00, 03, 00, 08, CT_ratio=OutRxPdo[3], state change update(18)
STOP 
==========================================================================
OutRxPdo[00]=CTL, OutRxPdo[01..7F]=Out[01..7F] 
InTxPdo[00]=SYS,  InTxPdo[01..7F]=In[01..7F] 
==========================================================================
8_bit + 16_bit + 32_bit
(00) - (07) : read_power_meter
(08) - (12) : read_system
(13) - (14) : set_DO0_DO1
(15) - (18) : set_parameter

address of power_meter = 04