Network Protocol Reference
Appendix B
Network Protocol Reference
Transmission procedure
The transmission between the external control equipment and the inverter takes the procedure below
Query
External control equipment
Response
Inverter
t
Latency time
(silent interval plus C078 setting)
•Query - A frame sent from the external control equipment to the inverter
•Response - A frame returned from inverter to the external control equipment
The inverter returns the response only after the inverter receives a query from the external control equipment and does not output the response positively. Each frame is formatted (with commands) as follows:
Frame Format
Header (silent interval)
Slave address
Function code
Data
Error check
trailer (silent interval)
Message Configuration: Query
Slave address:
•This is a number of 1 to 32 assigned to each inverter (slave). (Only the inverter having the address given as a slave address in the query can receive the query.)
•When slave address “0” is specified, the query can be addressed to all inverters simul- taneously. (Broadcasting)
•In broadcasting, you cannot call and loop back data.