LG GLOFA-GM Series, Руководство пользователя, Страница: 277 / 358

Chapter 8 Exercising program
8-26
2) Communication protocol
Communication protocol to communicate with MJ71UC24 computer link module is as follows.
[Figure 8.13] TX sequence of TX/RX frames
If GLOFA Cnet sends A) Read request frame first, MJ71UC24, to respond to this, reads data of applicable area
to transmit B) Response data frame, and Cnet I/F module sends C) Immediately Response frame to inform
MJ71UC24 of data received. Next is TX/RX frame structure.
A) Read request frame(Cnets’ request : Read request of 12 words in D0100 of station 1)
Classification Header
Station
No.
PLC No. Command
Message
wait
Head device
Number of
device
Frame ENQ 01 FF WR 0 D0100 0C
B) Response format to total Read (Response of MJ71UC24 side)
Classification Header
Station
No.
PLC No. Data Tail
Frame STX 01 FF Data (12 words) of D0100 address ETX
C) Immediate response
Classification Header Station No. PLC No.
Frame ACK 01 FF
Next is for communication frame contents. Refer to the user’s manual of GOLDSEC-M computer link unit for
more information.
Station No. : Station No.(station 1) of MJ71UC24
PLC No. : Set to FF
Command : WR (Total Read command of word unit in device memory)
GLOFA Cnet
User defined master
GOLDSEC MJ71UC24
Slave station 1
A) Read request frame
B) Response data
C) Immediate response frame