ICP CON I-7550E, Руководство пользователя, Страница: 23 / 102

I-7550E PROFIBUS/Ethernet Converter User Manual
(Version 1.00, June/2014)
PAGE: 23
Ethernet data with
1460 Bytes
PR
O
FI
BU
S
Input Data
(Max:240 Bytes)
Byte 0
Byte 239
.
.
.
.
.
.
.
.
.
2
nd
Package
Circular
Byte 19
System
setting
module
2
nd
Package
3
rd
Package
4
th
Package
5
th
Package
6
th
Package
7
th
Package
Figure 22 Partition Data of Ethernet device (2)
The user can get the information of these packages in input data area of
“System Setting module” (Please refer to section 3.3.2).
If the Ethernet devices transfer data too fast, it may cause FIFO overflow.
When it happens, the I-7550E will send diagnostic message to the PROFIBUS
Master (Please refer to section 4.4).
3.3 PROFIBUS I/O Data Area
The PROFIBUS Master sends and receives data in one telegram cycle. That is, the
master sends output data to the slave (I-7550E module) and receives input data
from the slave in a single cycle. The maximum length for each input and output
data is 240 bytes.
When the PROFIBUS Master sends data to I-7550E, it must transmit the
information of data to I-7550E e.g. data length
、
which Ethernet device will
receive data etc. Meanwhile, when Ethernet sends data to I-7550E, it also need
pass some information to I-7550E then the I-7550E could handle this data
according to this information.
So the I-7550E reserves the first 20 Bytes of Input/output data area and designs
the protocol of communication for data exchange. That means the user must
arrange and configure the “System Setting Module” before arranging the
input/output module. The user must add “System setting module” at the first