JUMO mTRON T Manual page 58

5 Ethernet transmission modes
Example: reading n words
Read the IP address of the central processing unit. Here in the example, it is the address
10.10.1.69. Since each IP address range is stored in a word, 4 words (8 bytes) must be read
out.
See also Modbus example in Chapter 3.6.2 "Reading n words", page 33.
Request:
MBAP header
00 01 00 00
2-byte 2-byte
transaction protocol ID
ID
Response Always 0x00
assignment with Modbus
to the
request (con-
secutive
numbering)
Response:
MBAP header
00 01 00 00
2-byte 2-byte
transaction protocol ID
ID
Response Always 0x00
assignment with Modbus
to the
request (con-
secutive
numbering)
58
00 06 FF
2-byte 1-byte
length unit ID
Length of the Always
request in 0xFF with
bytes starting TCP
(except for
with (incl.)
"unit ID"; 6 broadcast)
bytes here
(0x06)
00 0B FF
2-byte 1-byte
length unit ID
Length of the Always
response in 0xFF with
bytes starting TCP
with (incl.) (except for
"unit ID"; 11 broadcast)
bytes here
(0x0B)
Modbus telegram
(without slave address and CRC)
03 10 6D
1-byte 2-byte
function address
code first word
Function First word of
code for the IP
"reading n address to
words" be read
Modbus telegram
(without slave address and CRC)
03 08
1-byte 1-byte
function number of
code bytes read
Function 8 bytes were
code for read
"reading n
words"
00 04
2-byte
number of
words
4 words are
to be read
00 0A 00 0A 00 01 00 45
8-byte
data read
IP address consisting of 4
words (8 bytes):
10. 10. 1. 69