Mitsubishi Electric Melsec Q Series User Manual page 30

2 USING THE E-MAIL FUNCTION
Programmable
controller CPU
Subject
(ASCII data)
2
Main text
MSEND
(ASCII data)
instruc-
tion
Attached file
(binary data)
Ethernet
Programmable
module
controller CPU
MSEND
(Mail send)
Mail send
2 - 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
Encode
(Base64/7bit)
Encode
(7bit)
(Binary data)
Encode
(ASCII data)
(Base64)
(CSV data)
(3) Flow of the e-mail
The following diagram illustrates the flow of e-mail sent by the programmable
controller CPU to its reception by the external device:
Mail server
1) 2)
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 any mail has arrived at the inquiry interval
set with a programming tool 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 programmable controller CPU reads one e-mail and stores it in the mail
buffer of the programmable controller 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 are received using a mail user agent.
POINT
The e-mail send/reception function by the programmable controller 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.
When receiving e-mails
Mail Mail
server server
Subject
(ASCII data)
Main text
(ASCII data)
Attached file
(binary data)
Mail server
3)
Checks whether or not any mails
were received
Stores information
receive mail
Mails received
Request to receive mail
Stores receive mail
5)
MELSEC-Q/L
Programmable
controller CPU
(Does not decode)
Cannot be
MRECV
received
instruc-
tion
Decode
(Base64/7bit/8bit
/Quoted Printable)
Ethernet Programmable
module controller CPU
No mail
received
4)
Confirms
information of
receive mail
MRECV
(Reads receive
mail)
PC
2 - 2