Broadcast Communications; Precautions - Mitsubishi Electric MELSEC iQ-RJ71EN71 User Manual

Broadcast communications

Broadcast communications is a communication method that does not specify the external device. Data is exchanged between
all Ethernet-equipped module stations and external devices on the same Ethernet to which the Ethernet-equipped modules
are connected.
Item
Broadcast sending
Broadcast receiving
Setting procedure
Set "External Device Configuration" under "Basic Settings". ( Page 244 External Device Configuration)
1.
Select "UDP Connection Module" in "Module List" and drag it to "List of devices" or "Device map area".
2.
Set "Communication Method" for the external device to "Broadcast Send" or "Broadcast Receive".
3.
Set the other parameters required for communication in the connection.

Precautions

• Decide the dedicated port number for broadcast communication in the system, and use that number.
• Access via a router is not permitted when using broadcast send.
• The external device connected on the same Ethernet must carry out a read/discard processing if the message received
with broadcast receiving is not required.
Precautions
This section describes the precautions for communications using the fixed buffer.
Precautions for UDP/IP communications
Even if 'Open completion signal' (Un\G1900000 to Un\G1900007) is turned on, data sending may fail. If data sending fails,
send the data again.
Module FB and dedicated instruction
• When performing the open processing using the module FB or dedicated instruction, start sending and receiving data after
the module FB or dedicated instruction is completed.
• Multiple module FBs or dedicated instructions to one connection cannot be simultaneously executed. When multiple
module FBs or dedicated instructions are simultaneously executed, no operation is performed for the module FB or
dedicated instruction executed later. Execute again after the module FB or dedicated instruction in execution is completed.
1 FUNCTIONS
78
1.5 Communications Using the Fixed Buffer
Description
The same data is sent to all Ethernet devices on the same Ethernet.
The data sent with broadcast send is received.