Characteristics Of The Various Types Of Data Transmission - Siemens SIMATIC S5 Manual

S5-95U, SINEC L2
Table 1-7 lists the characteristics of the various types of data transmission to help you select the
best type for your specific application.
Table 1-7. Characteristics of the Various Types of Data Transmission
Characteristics
Via send and
Com- explicit
receive
muni-
mailboxes
ca-
tions implicit
1 to 242 bytes
Amount of
per job
data
In the flag area or
Send and
in the data area
receive data
may be
located
No
Parallel
processing of
several send
and receive
jobs
* Since no job is requested by the user in the case of implicit communications
EWA 4NEB 812 6112-02
Standard PLC-to-PLC
Connection Connection
Via L2-SEND FB
and L2 RECEIVE
FB
1 to 242 bytes per
job
In the flag area or
in the data area
Yes;
one send job and
one receive job in
parallel per
communications
partner
System Description
Cyclic I/O (ZP)
Via L2-SEND FB
and L2-RECEIVE
FB
Automatic, without
being initiated by
the user program
ZP master: 0 to 242 bytes per
Input range job
0 to 128 DW
Output range
0 to 128 DW
ZP slave:
Input range
0 to 121 DW
Output range
0 to 121 DW
In the flag area or
in the data area
In the data area
Non-applicable* Yes;
23 random jobs in
parallel
Layer 2 Access
1-15