Mitsubishi Electric melsec q03ud(E)cpu, Руководство пользователя

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CHAPTER 5 MC PROTOCOL COMMUNICATION
5
5.1 Sending a C
ommand fr
om an Ext
ernal Device to the
CPU Module
5.1.3 Pr
eca
utions
5.1.3
Precautions
(1) Number of devices
Only the external devices set in "Ethernet Conf." or "Open Setting" can be connected concurrently using MC
protocol.
Project window [Parameter] [PLC Parameter] [Built-in Ethernet Port Setting]
/ button
*1
*1 button can be used with the QnUDVCPU.
(2) Data communication frame
The following table lists the availability of data communication frames.
*1Available for the QnUDE(H)CPU with a serial number (first five digits) of "13102" or later
*2
Available for the High-speed Universal model QCPU with serial number (first five digits) of "18052" or later
*3 Even if the monitoring timer is set, the set value is ignored.
(3) Access range
• Only the connected CPU module can be accessed. Accessing another module will cause an error.
• In a multiple CPU system, other CPU modules not connected to Ethernet cannot be accessed.
• Accessing a CPU module on another station in CC-Link IE, MELSECNET/H, Ethernet or CC-Link via a
connected CPU module is not possible.
(4) When UDP is selected for Protocol
• If a new request message is sent to a UDP port after the previous request message is sent to the same port
and before no response is returned, the new request message will be discarded.
• Setting the same host station port number for multiple UDP connections is regarded as one setting. For
communication with multiple devices using the same host station port number, select TCP.
(5) File access during MC communication
The CPU module will perform file access processing prior to Ethernet communication processing. Because of
this, processing of the MC protocol function may be delayed if a file is accessed by FTP or a programming tool
during use of the MC protocol function.
When accessing a file while response time monitoring is performed on the connected device with the MC protocol
function, add the time required for file access to the monitoring time.
Communication frame Availability
4E frame
*2*3
QnA-compatible 3E frame
*3
A-compatible 1E frame
*1*3