Lg Electronics 120S 사용자 설명서

8-65 

 

 

3) Example program 2 

It’s supposed that MASTER-K120S main unit is the master and it reads Coil Status of the station no. 17, a Modicon product. 

            The master reads status of the input contact 10197 ~ 10218 of the slave station no. 17.   

            The input contact of the slave station is supposed to be as follows and the data that are read is saved in M015. 

   

Input 

10220  10219  10218  10217

10216

10215

10214

10213

10212

10211  10210  10209

Status 

X 

X 

1 1 0 1 0 1 1 1 0 1 

Hex 3 

5 

D 

Input 

10208  10207  10206  10205

10204

10203

10202

10201

10200

10199  10198  10197

Status 

1 0 1 1 1 0 1 0 1 1 0 0 

Hex B 

A 

C 

 

• The status of input contact 10219,10220 are redundancy. 

             

• Data is sent starting from the low bit by byte unit. If the deficient bit of a byte is filled with 0. An example of sending the  

above data is as follows. 

Example 2)    AC DB 35 

   
                  ① : It designates slave station and function code ( No. of station : h11(17) , function code : h02 ) 
                  ② :  Address setting 
              Address ‘0’ at MODBUS protocol means address ‘1’ actually .So if you want to designate address ‘10197’ ,                     

write address ‘10196’ 

                  ③ : Reading number setting ( Reading number is 22 from 10197 to 10220.) 
                  ④ : This is MODBUS Communication instruction. 
              The data transmission starts lower byte. The remnant part of byte is filled with ‘0’ 

⑤

  Stored data at D200,D201 are : 

 

Device 

Stored data 

D200 

h  AC  DB 

D201 

     h  00  35 

 

①

 

②

③

 

④