Registering Or Canceling Programmable Controller Cpu Monitoring For Serial Communication Modules - Mitsubishi MELSEC Q Series Reference Manual

3.17 Registering or Canceling Programmable Controller CPU Monitoring: for Serial
Communication Modules
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3 WHEN COMMUNICATING USING THE QnA COMPATIBLE 3E/3C/4C FRAMES OR 4E FRAME
These functions are for registering (including the start instruction) or canceling
programmable controller CPU monitoring from an external device or the programmable
controller CPU in order to utilize the programmable controller CPU monitoring function
of the C24.
By using the programmable controller CPU monitoring function, the external device
can receive the previously registered device data and abnormal CPU information or
message at a timing designated by a user.
This section explains the overview of the programmable controller CPU monitoring
function as well as how to use the commands to register/cancel programmable
controller CPU monitoring that are used by an external device communicating using
the MC protocol in order to perform the programmable controller CPU monitoring
function.
Please read the User's Manual (Application) before registering/canceling the
programmable controller CPU monitoring described in this section using the
programmable controller CPU monitoring function.
The User's Manual (Application) provides the details of the programmable controller
CPU monitoring function, its execution procedure, the message format for transmitting
information to an external device, how to register/cancel programmable controller CPU
monitoring from the programmable controller CPU, etc.
(1) Overview of the programmable controller CPU monitoring function
(a) The C24 monitors the following monitor information on the programmable
controller CPU, which should be registered by the user in advance.
• The numerical values stored in a word device
• The on/off status of a bit device
• The status of the programmable controller CPU of the local station
(whether any abnormality occurs)
(b) The C24 transmits the following user designated monitor information to an
external device when the monitor information satisfies the information
transmission condition designated by the user, or at a constant time interval.
(It is not necessary to process the transmission by the sequence program.)
• Multiple device data registered by a user or abnormal CPU information
(It is possible to transmit monitoring information by combined use with the
modem function)
If the information transmission to an external device by the
programmable controller CPU monitoring function occurs at the same
time as the following operations, it is performed at the same timing as the
data transmission by the on-demand function described in Section 3.11
(refer to Section 3.11.1 (3)).
• While transmitting a response message during communication using
the MC protocol.
• While receiving data from an external device in the half-duplex
communication.
(c) The C24 starts monitoring the programmable controller CPU when an
external device or the programmable controller CPU registers a
programmable controller CPU monitoring. The monitoring ends when an
external device or the programmable controller CPU cancels the
programmable controller CPU monitoring.
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