Programming Data Fragmentation - Siemens SIMATIC MV500 Operating Instructions Manual

Process interfacing via an automation system (PLC, PC)
9.4 Control with FB 79
m001:
9.4.4

Programming data fragmentation

Handshaking
The following sections introduce a handshaking procedure that ensures the consistency of all
the data transferred from the optical reader to the I/O controller regardless of any configured
consistency mechanisms in PROFINET. This procedure must be used with every data transfer,
even if the transfer only consists of one data block, for example when reading out the
program number selected on the optical reader.
182
//Enter data ID (in principle only necessary in the first cycle)
T DB17.DBD 4
L ED 13
T DB17.DBD 8
L ED 17
T DB17.DBD 12
L ED 21
T DB17.DBD 16
L ED 25
T DB17.DBD 20
L ED 29
T DB17.DBD 24
L EW 33
T DB17.DBW 28
L EB 35
T DB17.DBB 30 /
// Acknowledge with no. of data packet
L EB 5
T AB 5
BEA
// Store in DB
// Read next 4 bytes of user data
// Store in DB
// Read next 4 bytes of user data
// Store in DB
// Read next 4 bytes of user data
// Store in DB
// Read next 4 bytes of user data
// Store in DB
// Read next 4 bytes of user data
// Store in DB
// Read second last 2 bytes of user data
// Store in DB
// Read last byte of user data
// Store in DB
// Number of data packet
// Send as acknowledgment to optical reader
Operating Instructions, 03/2021, C79000-G8976-C494-05
SIMATIC MV500