Sample Program For Data Exchange, If Code Length ”  %\Whv - Siemens SIMATIC VS130 Series Manual

Controlling with a PLC
"Send" User Data Interface
Byte Meaning
No.
0 reserved
1 Consecutive number of the data packet to be sent to the DP master
2 Net total length of the data to be transmitted in bytes (in STEP 7 format)
3
4 1st user data byte
5 2nd user data byte
... ...
31 28th user data byte
"Receive" User Data Interface
Byte Meaning
No.
0 reserved
1 Consecutive number of the latest data packet correctly received from the DP
master
2 reserved
... ...
31 reserved

Sample Program for Data Exchange, if Code Length ”  %\WHV

6.2.3
Below, you will see a sample program for data exchange when the code length is a
maximum of 28 bytes.
Explanation of the Program
The DP master does not check how many bytes the processing unit has supplied,
but always reads 28 bytes without any monitoring.
The start of the "Send" user data interface is at address 4 of the process image
input table. The start of the "Receive" user data interface is at address 4 of the
process image output table.
To ensure consistency over the entire range (32 bytes) there must be no process
image update during the program shown below.
The user data are stored in data block DB17 starting at byte 4.
6-8
Vision Sensor VS 130
A5E00199459-01