14-19
14 Serial Communications
CP1E CPU Unit Software User’s Manual(W480)
14-4 Modbus-RTU Easy Master Function
14
14-4-4 Programming Examples
DM Area Data
DM Fixed Allocation Words for Modbus-RTU Easy Master
DM Area data in words D1301 to D1305 are set before the execution of the ladder program.
D1306 and D1307 do not need to be set. They are modified by MOV instructions, and are used to
change, start, and stop frequency references.
RUN Command (Register 0001) Allocation and Details for Inverter 3G3MV
For this example, only the RUN command (bit 00) will be used.
• With the Modbus-RTU Easy Master, a CRC-16 checksum does not need to be set in the DM Area,
because it is calculated automatically.
Bit No. Setting
0 RUN command (1: Start)
1 Normal/reverse rotation (1: Reversed)
2 External error (1: EF0)
3 Error reset (1: Error reset)
4 Multifunction input 1 (1: ON)
5 Multifunction input 2 (1: ON)
6 Multifunction input 3 (1: ON)
7 Multifunction input 4 (1: ON)
8 Multifunction input 5 (1: ON)
9 Multifunction input 6 (1: ON)
10 Multifunction input 7 (1: ON)
11 to 15 (Not used.)
Serial Option Port: Command
Setting
Address
Value
Slave
address
Function
code
Communications
data bytes
Communications data: D1303 to D1349 (maximum)
94 bytes (47 words) max.
Inverter slave
address: 1 hex
Inverter data write:
10 hex
Use the 9 bytes from the upper byte
of D1303 to the upper byte of D1307
Register number for starting data write:
0001 (Specifies to start writing data to
Inverter starting at register 0001.)
Number of registers written:
2 (data for registers 0001 and 0002)
Attached data size in bytes:
4 (4 bytes from lower byte of D1305
to upper byte of D1307)
Data for starting register
(e.g. set 0001 hex for register 0001
(RUN command, see below))
Data for next reigister
(e.g. set 60.0 Hz (0258
hex) for register 0002
(frequency reference))
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