Hitachi L2002 - Manual (Page 242)

Network Protocol Reference
Appendix B
B–6
Network Protocol Reference
Transmission procedure
The transmission between the external control equipment and the inverter takes the
procedure below
• 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:
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.
Frame Format
Header (silent interval)
Slave address
Function code
Data
Error check
trailer (silent interval)
Query
t
External control
equipment
Response
Inverter
Latency time
(silent interval plus C078 setting)