Instruction And Examples - LG MASTER-K 120S Series User Manual

Chapter 8 Communication Functions
8.3.4 Instruction and example
1) MODBUS communication instruction(MODCOM)
MODCOM MODBUS communication
Instruction
M P
Ch
S1
○ ○
S2
○ ○
S3
○ ○
Flag
Error flag turns on when designating area is over
Error
and the instruction isn't executed
(F110)
■ MODCOM Ch S1
(1) Example program
• Designate slave station No. , function code,.address, No. of reading
• When input condition(M0020) turns on, MODBUS communication starts.
• Receiving data are stored D1000, and communication status is stored to M100
• When operates as slave, MASTER-K120S responses to master station without commands. And When operates as master,
MASTER-K120S sends data in S1 with MODBUS protocol at rising edges of execution condition.
Available device
K L F T C
○ ○ ○ ○ ○
○ ○ ○ ○
○ ○ ○ ○
S2 S3
S D D i n teger
#
○
○ ○
○ ○
○ ○
Designation
Ch Designated communication channel
S1 Device which is registered communication parameter
S2 Device which stored communication data
S3 Device which stored communication status
8-62
Flag
No. of
Error Zero
steps
(F110) (F111)
7
○
Carry
(F112)