Monitor Device Memory (Command: 06, 07, 08, 09) - Mitsubishi Electric MELSEC IQ-R series Reference Manual

Monitor device memory (command: 06, 07, 08, 09)

The ON/OFF status or contents of devices in the CPU module can be monitored from an external device by registering the
devices and device numbers to be monitored to E71 in advance and executing the monitor command from the external
device.
When reading device memory in batch, the read device numbers will be consecutive. However, when reading them using the
monitor command, the devices can be monitored randomly by specifying the arbitrary devices and device numbers.
For monitoring the extended file register, refer to the following section.
Page 425 Monitor extended file registers (command: 1A, 1B)
Procedure for monitoring
1.
Register the devices to be monitored from the external device to E71 by registering monitor data.
2.
Execute the read processing by a monitor command.
3.
Process the data.
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 is deleted when turning the power OFF or the resetting the CPU
module.
• There are three types of commands for monitor data registration; expansion file register, device memory bit
unit, and device memory word unit. The recently registered one command out of three types of commands
can be registered to E71.
• When registering device memory of the CPU module as a monitoring 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.
18 COMMUNICATING USING 1E FRAMES
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18.4 Read and Write Device Memory