power meter to plc

hi Friends
Does anyone have a sample program from method connect plc to power meter Through RS485 ?
No matter the type of Plc

I've done this recently (24 Schneider PM3250's on RS-485) with an M340 as the modbus master.

but that's not going to be much use to you if you're using a different PLC.

So tell us what model of PLC and Power meter you're likely to be using and I'm sure someone can provide more details. But no one's going to hand you a nice little project for you to just download.

It's a pretty simple application really - all I do is cycle through each meter's address, read it's registers over modbus using READ_VARS in Unity (the register list and addresses will be provided in the documentation from the meter manufacturer), and then copy them to an array of a custom data type I put together. if there's no response from the meter then set all variables to zero and raise a comms fail flag.

thank you for response
my plc : cp-1015 from tecomat plc
my power meter : SMM 33 from kmb company

Well it looks like your PLC supports modbus over RS-485 with an expansion module on comm port 2. The base CPU only has RS-232 which isn't much good if you've got multiple meters.

Your power meter also supports modbus over RS-485, provided you've ordered the one with this option.

tecomat have a library with functions for using modbus RTU - see document here:

http://www.tecomat.com/wpimages/other/DOCS/eng/TXV00352_02_Mosaic_ModbusRTULib_en.pdf

I would read that carefully, download the library, set up your meter and PLC on the bench and just have a go at reading a register from it.

thank you very much for response
Excuse me , I'm very inexperienced

Suppose I want to read I1 and I2,
Registers are as follows in power meter:
http://upload.tehran98.com/upme/uploads/f0095208f51ce7951.jpg

How should i change below program

VAR_GLOBAL

I1 : BYTE;

I2 : BYTE;

CmdCH2 : ARRAY [1..2] OF TCmdStruct; // Modbus commands array for channel CH2 control

END_VAR

PROGRAM prgMain

VAR

END_VAR

ModbusCmd(Gr:=1,FNC:=03,SNo:=1,StAdr:=0x0005,NoPoint:=1,PtrData:=adr(current),Cmd:=CmdCH2[1]);

ModbusCmd(Gr:=1,FNC:=03,SNo:=2,StAdr:=0x0008,NoPoint:=1,PtrData:=adr(current 2), Cmd:=CmdCH2[2]);
//description in below figure :
http://upload.tehran98.com/upme/uploads/5e056280e791e2fa1.jpg

DO is now value I1 into variable current ??

END_PROGRAM