User manual

20 Modbus RTU MN744
Text Handling Continued
Read Units Text
(Sub-Code 9)
This PDU is used to read units text from the control card.
Request PDU
Byte 1
Byte 2 Byte 3
Function Code (66) Sub-Code (9) Units Test ID
Where,
Byte 1: Text Handing Function Code 66 (0x42)
Byte 2: Read Units Text Sub-Code
Byte 3: Units text ID as defined in parameter configuration PDU
Response PDU:
Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte N
Function Code (66) Sub-Code (9) Units Test ID ASCII ASCII NULL
Where,
Byte 4-N: Up to three character units text
Language independent
Write List Parameter Text (Sub-Code 10)
This PDU is used to write list parameter text to the control card.
Request PDU
Byte 1
Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 . . . Byte N-1 Byte N
Function Code (66) Sub-Code (10) PN H PN L Index H Index L ASCII . . . ASCII NULL
Where,
Byte 1: Text Handing Function Code 66 (0x42)
Byte 2: Write List Parameter Text Sub-Code
Byte 3-4: 16-Bit Parameter Number (PN)
Byte 5-6: 16-Bit Index (1-Max) into List
Byte 7-N: 1 to 16 character Null terminated ASCII text string
Response PDU:
Byte 1
Byte 2 Byte 3 Byte 4 Byte 5 Byte 6
Function Code (66) Sub-Code (10) PN H PN L Index H Index L
Where,
Byte 4-N: Up to three character units text
Language independent