Automation Direct D0-DCM, Руководство пользователя

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MODBUS R
T
U
D0–DCM with
5–2
D0–DCM Using MODBUS
DL05/06 Data Communications Module, 1st Edition, 08/05
Network Slave Operation
This section describes how a MODBUS RTU master on a network can communicate
with a D0–DCM using the MODBUS RTU protocol. A network master must send a
MODBUS function code and MODBUS address to specify a PLC memory location in
the DL05/06 CPU. No CPU ladder logic is required to support MODBUS slave
operation.
The D0–DCM supports the following MODBUS function codes when acting as a
MODBUS slave.
MODBUS
Function Code
Function DL05/06
Data Types Available
01 Read Output Table Y, C, T, CT
02 Read Input Table X, SP
03 Read Holding Registers (when addressing
mode is 584/984, this function is used to ac-
cess analog output registers) V
04 Read Input Registers (when addressing mode
is 584/984, this function is used to access
analog input registers) V
05 Force Single Output Y, C, T, CT
06 Preset Single Registers V
08 Loop back / Maintenance
15 Force Multiple Outputs Y, C, T, CT
16 Preset Multiple Registers V
There are typically two ways that most MODBUS addressing conventions allow you
to specify a PLC memory location. These are:
•
By specifying the MODBUS data type and address
• By specifying a MODBUS address only.
MODBUS Function
Codes Supported
Determining the
MODBUS Address