SAMWONTECH
1th Edition of TEMP1000_Series IM : Apr. 2014 Page 20 / 63
6.3 Function code - 03
Function code-03 is used to read the data of consecutive D-Register block in sequence up to 64 registers.
▣ Request Message Frame
Factor
ASCII
RTU
Protocol Header
:(Colon)
-
Slave Address
2 characters
8-Bit
Function code-03
2 characters
8-Bit
D-Register Hi
2 characters
8-Bit
D-Register Lo
2 characters
8-Bit
Address Count Hi
2 characters
8-Bit
Address Count Lo
2 characters
8-Bit
Error detecting
2 characters
16-Bit
Protocol Tail
2 characters (CR+LF)
-
◈ Exmaple
Request message to read the D-Register FROM D0001 (NPV) TO D0002 (NSP) should be
- MODBUS ASCII
:010300000002FA[cr][lf]
- MODBUS RTU
010300000002C40B
☞
D-Register has to be subtracted ‘1’ from the designated address number on D-Register table in this manual.
▣ Response Message Frame
Factor
ASCII
RTU
Protocol Header
:(Colon)
-
Slave Address
2 characters
8-Bit
Function code-03
2 characters
8-Bit
Data byte count
2 characters
8-Bit
Data - 1 Hi
2 characters
8-Bit
Data - 1 Lo
2 characters
8-Bit
…
…
…
Data - n Hi
2 characters
8-Bit
Data - n Lo
2 characters
8-Bit
Error detecting
2 characters
16-Bit
Protocol Tail
2 characters (CR+LF)
-
◈ Exmaple
Response data will be same as below, when 25.0 of D0001 (NPV) and 100.0 of D0002 (NSP)
- MODBUS ASCII
:01030400FA03E813[cr][lf]
- MODBUS RTU
01030400FA03E8DABC
