LSIS XBE-DC08A, User Manual, Page: 1080 / 1284

Chapter 2 Built-in Cnet communication
2-82
B
u
ilt
-in
C
omm
(b) Response frame (receiving normal frame)
Classification
Station
no.
Function
code
No. of byte Data Error check
Frame 01 03 06 13 12 3D 12 40 4F CRC
(c) Response frame (receiving abnormal frame)
Classification Station no. Function code Exceptional code Error check
Frame 01 83 04 CRC
7) Reading data of word type at the word input (04)
(1) Reading word of input area
In case of reading word of input area, request and response frame is as follows.
Tail of frame is applied in case of ASCII mode.
(a) Request frame
Classification
Station
no.
Function code
(04)
Address Data size Frame error check Tail (CRLF)
Size (byte) 1 1 2 2 2 2
(b) Response frame (In case of receiving normal frame)
Classification
Station
no.
Function code
(04)
No. of byte Data Frame error check Tail (CRLF)
Size (byte) 1 1 2 N*2 2 2
(c) In case of response frame (In case of receiving abnormal frame)
Classification Station no. Error code
Exceptional
code
Tail (CRLF)
Size (byte) 1 1 1 2
(2) Details of frame
(a) Station no.: indicates the station no. of slave to read word of input area.
(b) Function code: ‘04’ indicating Read Input Registers
(c) Address: start address of data to read and it consists of 2 byte. At this time, start address conforms to modbus
address regulation.
(d) Data size: size of data to read and it consists of 2 byte.
(e) Frame error check: in case of ASCII mode, it uses LRC and in case of STU mode, it uses CRC. It consists of 2
byte.
(f) Tail: it is applies in case of ASCII mode, CRLF is added after LRC.
(g) No. of byte: no. of byte of response data
(h) Data: makes address of request frame as start address and transmits data with byte unit. At this time, since data
is word type, it is double of no. of byte.
(i) Error code: error code is expressed by adding 80(Hex) to function code and in case of reading word of input area,
it is expressed as 84(Hex).
(j) Exceptional code: indicates detail of error and consists of 1 byte