Mitsubishi Electric FR-F820-00077 Instruction Manual page 662

(N) Operation via communication and its settings
Message format
Programmable controller
Programmable controller
Fig. 5-242:
● Data check time
Item
Various monitors, operation command, Frequency setting (RAM)
Parameter read/write, Frequency setting (EEPROM)
Parameter clear / all clear
Reset command
Tab. 5-241: Data check time
● Query
A message is sent to the slave (for instance, the inverter) having the address specified by the
master.
● Normal Response
After the query from the master is received, the slave executes the request function, and returns
the corresponding normal response to the master.
● Error Response
When an invalid function code, address or data is received by the slave, the error response is
returned to the master.
This response is appended with an error code that indicates the reason why the request from the
master could not be executed.
This response cannot be returned for errors, detected by the hardware, frame error and CRC check
error.
● Broadcast
The master can broadcast messages to all slaves by specifying address 0. All slaves that receive a
message from the master execute the requested function. With this type of communication, slaves
do not return a response to the master.
NOTE During broadcast communication, functions are executed regarded of the set inverter station
number (Pr. 331).
5 - 490
Query communication
Query message
(Master)
Inverter (slave)
Broadcast communication
Query message
(Master)
Inverter (slave)
Message format
Inverter response time
(Refer to the following table for the data
check time)
Response message
Data absence time
(3.5 bytes or more)
No response
Check time
< 12 ms
< 30 ms
< 5 s
No answer
Parameters
I001227E