Monitoring Extension File Register - Mitsubishi MELSEC Q Series Reference Manual

5.3.9 Monitoring extension file register

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The monitor data registration function registers the name and number of the devices to
be monitored from an external device to the C24.
The monitor function allows to read the data contents of the registered devices from
the programmable controller CPU and processing it in the external device.
When the batch read (ER) or direct read (NR) is used to read the devices, the device
numbers must be consecutive. However, by using the monitor data registration
function, devices can be monitored by designating the device numbers freely.
The following example illustrates the control procedure for monitoring and registering
name and number of the devices to be monitored to the C24.
(1) Monitoring procedure
Monitor
Process monitor data registration
Editing EM commands and
transmitting device designation
Process read
(ME command execution)
Process data
(CRT display, etc.)
NO
Change monitor device?
YES
POINT
(1) Monitor data must always be registered when monitoring using the procedure
shown above. If the monitoring is performed without registering the monitor
data, a protocol error will be generated.
(2) The contents of registered monitor data are deleted when the C24 is rebooted.
(3) Five kinds of monitor data can be registered for each command of the
extension file register (EM), and device memory in bit units (BM or JM) and
word units (WM or QM).
(4) When multiple external devices registers the monitor data in the
programmable controller CPU device memory of the same station, the
registered data is overwritten, and the device memory that was registered last
becomes valid.
Refer to section 5.2.8 for details about monitoring the device memory.
5 WHEN COMMUNICATING USING THE A COMPATIBLE 1C FRAMES
EM ...... ACPU common commands
ME ...... ACPU common commands
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