Network Protocol Reference - Hitachi L2002 Instruction Manual

B–6

Network Protocol Reference

Network Protocol Reference

Transmission procedure
The transmission between the external control equipment and the inverter takes the
procedure below
External control
equipment
Inverter
• 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:
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.
Query
(silent interval plus C078 setting)
Frame Format
Response
Latency time
t