Read EM6400 Multifunction Meter parameter value from M340 on Modbus network

Hardware used:- M340 (BMX P34 2030) EM6400 Multifunction Meter Cable connection:- 1) RS485 Modbus Port of EM6400 Meter has been connected with Modbus cable with Modbus port of M340 PLC. 2) The pins used by the RS485 serial link and EM6400 Multifunction meter are:

Procedure:

> Open the Unity Pro Software and select the correct M340 processor as we are using i.e. BMX P34 20102 02.10

> Now open the M340 CPU & add the module in the Unity pro file.

>All the configuration checked in the Modbus configuration. Do all the setting which require as per your specification

> Create a new section.

> Named a new "empty" section as “Test_EM6400” and Select the programming language of the section in “LADDER”, select the type of access protection to “None”

> Calling a function block using the function input assistant

> Select the desired function block in our case READ_VAR.

> Select the desired function block in our case ADDM (Address Conversion). The ADDM function is used to convert a character string into an address that can be used directly by the following communication functions: READ_VAR, WRITE_VAR etc

> Enable both Function Blocks ADDM and READ_VAR by “Boolean Link”

> Addressing string syntax in (parameter IN) i.e. Device address on bus or network as shown.

> Provide input parameter “ADDRESS_METER” in which can be used as an input parameter for several communication functions

> Provide type of objects to read for Modicon M340 ’%MW’ : internal words

> Provide Index of the first object to read. In our case we are reading Total RMS block Address 3001 to 3020 (Total number of registers 20)

> Enter Number of objects to read 20

> Enter Management_Param

> Enter Receiving Array “RESULT” Word table containing the value of the objects read

> Go to Project Setting

> Select Allow dynamic arrays (ANY_ARRAY_XXX) & Directly represented array variables in Variables

> Select Elementary Variables as shown and MANAGEMENT_PARAM

> Select Result Array type 0..20 OF INT

> Provide Address %MW100

> Rebuild All Project

> Ensure there are no Errors

> Connect PLC

> Download project to PLC.

> Wait until for end of transfer of project to PLC

> PLC is RUN mode and Project is now EQUAL

> Add Parameters of RMS Block as shown in screen.

> Now make an animation table in the Unity Pro.

> Select the Instances as required in Animation table.

> Now you could see the reading parameters are added and displaying the real time values.

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