LS Industrial Systems GLOFA G7M-DR20U, Руководство пользователя

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Chapter 8. Communication Function
8-79
8.3.5 Example
According to the settings for the device supporting Modbus protocol, setting of GM7U basic unit is changed, but this example
explains Modbus protocol communication among GM7U units.
The slave station program: This outputs the received data saved in M area through the output coil.
The master station program: It saves 16#FF (or 255) at %MW0 (It is coincided with %MX0 ~ MX15 or %MB0 ~ %MB1) in
function block MOD0506 (function code 06), then reads %MX0 through MOD0102 (function code 01), and again saves 0
at %MX0 ~ %MX9 using function block MOD1516 (function code 15), then reads %MW0 through Mod0304.
The cable used in this example is same with that used for the dedicated protocol communication between GM7U’s.
1) Slave station setting and a program
(1) Open a new project file and a new program for the slave station.
(2)
Select communication parameter in GMWIN parameter and the following window opens.
-
Set parameters as the following table.
Communication Method Protocol and Mode
Station
No.
Baud
Rate
Data
Bit
Parity
Bit
Stop
Bit
Communication Channel Modbus
Transmission
Mode
17 38400 7 Even 1
RS-232C Null Modem or
RS - 422/485
Slave ASCII