User manual

5 Universal (General-purpose communication)
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5.4 Universal protocol
Modbus RTU is a standard. It communicates with host unit as master, GP/LP as slave. In host
unit, it transmits Query to GP/LP, GP/LP executes designated operation according to received
command and send response. When it receives Query of master and slave does not respond
ecause of detection of error including parity, CRC or communication error, master re-transmits
Query as timeout.
 Normal communication
 When there is no response
※ For more details, refer to general modbus protcol manual.
5.4.1 Available address
It uses UB, UW device as GP/LP inner memory.
Type Device
Range
Enable
read/write
Start
End
Bit
Coil UB150 UB4095F Write
Input status UB0 UB4095F Read
Word
Input register UW0 UW6047 Read
Holding register UW15 UW6047 Write
5.4.2 Available function code
There are several functions for using Modbus. Available functions in GP/LP general-purpose
communication are four as below.
Code Function Read/Write Description
01 Read Coils Read
Read the appropriate
address
15 Force Multiple Coils Write
Write the appropriate
address
03 Read Holding Register Read
Read the appropriate
address
16 Force Multiple Register Write
Write the appropriate
address
Additional function code will be upgraded.