CMC SV008ACtionMaster-2, Installation And Operating Instructions Manual

Page: 85 / 119

Chapter 5 - MODBUS-RTU Communication
79
Request for Write
ENQ Drive No. CMD Address
The number of
address to
write
Data SUM EOT
05h “01” ~ “1F” “W” “XXXX” “1” ~ “8” = n “XXXX…” “XX” 04h
1 byte 2 bytes 1 byte 4 bytes 1 byte n * 4 bytes 2 1
Total byte = 12 + n * 4 = max. 44 bytes
Acknowledge Response
ACK Drive No. CMD Data SUM EOT
06h “01” ~ “1F” “W” “XXXX…” “XX” 04h
1 byte 2 bytes 1 byte n * 4 bytes 2 bytes 1 byte
Total byte = 7 + n * 4 = max. 39 bytes
Negative Acknowledge Response
NAK Drive No. CMD Error Code SUM EOT
15h “01” ~ “1F” “W” “**” “XX” 04h
1 byte 2 bytes 1 byte 2 bytes 2 bytes 1 byte
Total byte = 9 bytes
Note) As for Run and Frequency command, when Request for Write and Acknowledge Response is exchanged
between pc and inverter for the first time, previous data is returned. In this case, Request for Write Twice.
From the second time of transmission, the exactly same data will be transmitted
.
Request for Monitor Registration: This is useful when constant parameter monitoring and data
updates are required.
Request for Registration of ‘n’ numbers of Address
ENQ Drive No. CMD
The number
of address
to monitor
Address SUM EOT
05h
“01” ~
“X”
“1” ~
“XXXX…” “XX” 04h
1 byte 2 bytes 1 byte 1 byte
n * 4
2 bytes 1 byte
Total byte = 8 + n * 4 = max. 40 bytes
Acknowledge Response
ACK Drive No. CMD SUM EOT
06h “01” ~ “1F” “X” “XX” 04h
1 byte 2 bytes 1 byte 2 bytes 1 byte
Total byte = 7 bytes