Siemens SIMATIC S5-95U - Page 44

Computer Link with 3964(R) Transmission Protocol S5-95U, Second Serial Interface
Mode number for computer link (MOD)
Two modes are available for the type of data transmission.
Table 3-4 shows the meanings of the individual mode numbers.
Table 3-4 Meanings of the Mode Numbers
Mode Meaning
1 No block check character is sent at the end of a transmitted data
block (3964).
A block check character (BCC) is sent at the end of a transmitted
data block (3964R).
2
Default in
DB1:
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a
X
Parameter set for computer link (PAR)
The defaults necessary for data exchange are entered in the parameter set.
The following is to be specified in DB1:
• Data block / flag byte to include the parameter set (in DBx, from DW y onwards)
• All parameters of the parameter set ( Table 3-3).
Access to parameterization data ( Figure 3-8):
• The DB1 interpreter stores the parameters ”PAR”, ”SF”, ”EF”, ”KBS”, ”KBE” and ”MOD”
in the system data from system data word 48 onwards ( Appendix B).
• The DB1 interpreter stores the parameters of the parameter set in the DBx defined in the
system data, starting from DWy.
• The driver for the computer link in the operating system of the PLC accesses the
parameterization data as described in Figure 3-8.
Section 3.5 includes an example DB1 and the associated parameter set DB.
Figure 3-8 Access to Parameterization Data in a Computer Link
Parameter set
Transfer:
cyclically every 100 ms
Transfer in case of
• PLC POWER ON or
• DB1 change of the
parameter set or
• Mode change
Stored in PLC if
• STOP RUN or
• POWER ON RUN
DB1
Position of the parameter set
DW y
DBx
System data
SD 48
a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a
a a a a a a a a a a a a a a a a a
a
a a a a a a a a a a a a a a a a a a a
Driver for
computer
link
in
operating
system
...
RKT:
PAR DBxDWy
...
BDR xxxx ...
3-12 EWA 4NEB 812 6095-02