Refresh-FB for Modbus communication CJ/CS with SCU or CP1 to MX2 and JX/MX-inverter

Introduction

To use MX2 and JX/MX inverter connected to a PLC with Modbus protocol a new version of the Function Block _INV002_Refresh.cxf (known from the CX-Programmer's library) is needed:  INV_Refresh_X31_.cxf.

Hardware needed

• CJ / CS1-PLC with SCU/SCB or CP1H / CP1L (except 10 point) 
• MX2 and JX/MX inverter 

Cable connections

CX-Programmer setup

There is an example CX-Programmer project attached. If you already know the Function Block from the library called _INV002_Refresh, you will find that only some status bits are missing and the set frequency has to be changed to be transmitted.
 

This version from July 2010 supports following inverters:
 MX2 and JX/MX .

It is smaller than the original, but can handle all Modbus node numbers from 1 to 31 (31 total on one PLC port).
The main difference is the improved error handling:
If the communication is broken, Bit15 (error bit) is turned ON and all other status bits are turned OFF.

The version from March 2010 had several changes compared to the version from November 2009.

command bit 0 is always Forward Run,
command bit 1 is always Reverse Run.
It is possible to choose the type of inverter with FB-parameter ModelTypJX,
a bit has to be set for every inverter address, which is JX or MX, like in the scan list;
Bit = 1 means older type JX or MX
Bit = 0 means type MX2 

• the FB is much smaller than the original from the library, you will have much more space left for the main program.
  Some status bits are not read out of a JX/MX (Bit 4 = Zero speed,Bit 10 = Under voltage)
• The original FBs from the library ParameterRead and ParameterWrite work with this version of Refresh-FB, but some double word parameters of JX cannot be accessed.
  You have to use new ReadNoParameter WriteNoParameter-FB.
  The example has been changed, to present a changed set frequency during run to the Refresh-FB.
•  
• You should also set the SCUs port “Serial Gateway Response Time out” to e.g. 300ms
   

CP1W-CIF11 setup

Put all DIP switches to ON except DIP 4 = OFF (RS485 with termination)

MX2 parameter settings

Open manual I114-EN-01 and go to section B2. Here are the parameters that need to be set to make sure MX2 is able to communicate. Match the parameters of MX2 inverter to the settings in the PLC. After changing the settings recycle power of the MX2. If parameters are set properly, communication between PLC and MX2 is established.

Set following settings in MX2 and cycle the power:
A001: 3      Frequency source
A002: 3      Run command source
C071: 05    9600 bps
C072: 1      Modbus address
C074: 01    Even parity
C075: 1      Stop bits

To learn more about the benefits of Modbus integration on a real pack stacking machine, explore the customer reference at the packaging solutions area. 

Link:
http://www.myomron.com/index.php?action=kb&print=1278