Monitor (Command: Em, Me) - Mitsubishi Electric MELSEC IQ-R series Reference Manual

Monitor (command: EM, ME)

The monitor data registration function registers the devices and numbers to be monitored from an external device to C24.
The monitor function reads the data of the registered devices from the CPU module and processes it in the external device.
When the batch read (ER) or direct read (NR) is performed, the read device numbers will be consecutive, however, by using
this function, devices can be monitored by specifying the device numbers randomly.
The following example shows the control procedure for monitoring and registering name and number of the devices to be
monitored to the C24.
Monitoring procedure
1.
Process the monitor data registration (Edit of EM command and transmission of device specification.)
• Page 379 Register monitor data (command: EM)
2.
Perform read process. (Execution of ME command)
• Page 380 Monitor (command: ME)
3.
Process the data. (Screen display, etc.)
4.
If do not change the devices to be monitored, return to step 2, and repeat the process.
• When monitoring data as the procedure shown above, the monitor data registration is required. If monitoring
data without registering the data, a protocol error occurs.
• The content of registered monitor data are deleted when C24 is rebooted.
• Five kinds of monitor data can be registered for the extended file register (EM), device memory in bit units
(BM or JM), and word units (WM or QM).
• When registering device memory of the CPU module as a monitor data from more than one external
devices on the same station, the recently registered device memory will be available since the registration
data is overwritten. (Monitoring device memory Page 366 Monitor (Command: BM, JM, WM, QM, MB,
MJ, MN, MQ))
17 COMMUNICATING USING 1C FRAMES
378
17.5 Read and Write Extended File Register