Download IPM3300 Multi-Function Power Meter User guide

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IPM3300 User Guide
5.2 Modbus
In the start of modus communication, master will issue a “Query” to the slave. Every slave will monitor
the “Query” address, so as to “execute’ or give “response” when the address is right
5.2.1 Modbus Format
The Query-Response Cycle
Slave 1
Slave 2
Slave 3
Slave n
Master
Query
Response
Query message from Master
Device Address
Device Address
Function Code
Function Code
8 bit Data Bytes
8 bit Data Bytes
Error Check
Error Check
Response messages from Slave
5.3 Communication protocol
IPM3300 use Modus RTU as the communication protocol. The following shows Query and Response
format.
Query：
Slave
Address
Function
Code
0x03,
0x04
Response：
Slave Function
Addre Code
ss
0x03,
0x04
Start
Address
(Hi)
Byte
Count
Start
Address
(Lo)
Data
(Hi)
Number
of Points
(Hi)
Data
(Lo)
Number
of Points
(Lo)
Error
Check
(Lo)
20
Error
Check
(Lo)
Error
Check
(Hi)
Error
Check
(Hi)