Mitsubishi QJ71E71-100 Series, Руководство пользователя

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MELSEC-Q
2 USING THE E-MAIL FUNCTION
2
(2) Data conversion method used by the Ethernet module
The following shows the data conversion method used by the Ethernet module.
When sending e-mails When receiving e-mails
PLC
CPU
MSEND
instruc-
tion
Subject
(ASCII data)
Main text
(ASCII data)
Attached file
(binary data)
(Binary data)
(ASCII data)
(CSV data)
(Does not decode)
Encode
(Base64)
Cannot be
received
Mail
server
Mail
server
Attached file
(binary data)
MRECV
instruc-
tion
Subject
(ASCII data)
Main text
(ASCII data)
Decode
(Base64/7bit/8bit
/Quoted Printable)
Encode
(7bit)
Encode
(Base64/7bit)
PLC
CPU
(3) Flow of the e-mail
The following diagram illustrates the flow of e-mail sent by the PLC CPU to its
reception by the external device:
PLC
CPU
MSEND
(Mail send)
Mail send
Ethernet
module
Mail server
PC
1) 2)
5)
Checks whether or not any mails
were received
Stores receive mail
MRECV
(Reads receive
mail)
3)
4)
Confirms
information of
receive mail
Stores information
receive mail
Request to receive mail
No mail
received
Mails received
Mail server
PLC
CPU
Ethernet
module
1) Send an e-mail to the send mail server of the local station's Ethernet module.
2) The send mail server of the local station's Ethernet module sends the e-mail
to the receive mail server of the send destination device.
[When receiving by the Ethernet module]
3) The Ethernet module checks whether or not any mails have arrived at the inquiry
interval set with GX Developer, and stores the results to the buffer memory.
4) By executing the MRECV instruction, the Ethernet module reads e-mails from
the e-mail server to the mail buffer.
The PLC CPU reads one e-mail and stores it in the mail buffer of the PLC
CPU's device.
By user designation with the MRECV instruction, the Ethernet module
reads the number of remaining receive mails on the mail server and
stores this number in the buffer memory.
[When receiving by a PC]
5) Mails can be received using applications such as Internet Mail.
POINT
The e-mail send/reception function by the PLC CPU and the communication
function using the random access buffer cannot be used together. Only one of
them can be used at any given time.