Recommended Types Of Data Transmission - Siemens SIMATIC S5 Manual

System Description
• Is my S5-95U to be a passive or active station on the LAN?
An active station receives the token (permission to send). When they have the token, active
stations can send data to other stations.
A passive station does not receive the token. Consequently, passive stations can only exchange
data with an active station when they are requested to do so by that station.
An S5-95U should, if possible, be a passive station on the LAN since token management on an
active station takes time and increases the LAN's response time.
• Which type of data transmission should I choose?
You will find the answer to this question
- in Table 1-6 (recommended types of data transmission)
- in Table 1-7 (comparison of the characteristics of the various types of data transmission)
- in Tables 1-8 and 1-9 (which type of data transmission is to be recommended for which
station)
Table 1-6. Recommended Types of Data Transmission
Type of Data
Transmission ......
Standard connection
PLC-to-PLC connection
Cyclic I/O
Layer 2 access
1-14
...generally recommended for:
Porting existing programs from SINEC L1 to SINEC L2.
Communications between two active stations.
Communications between active and passive stations.
Communications with non-SIMATIC devices which cannot exchange
data via the standard connection, PLC-to-PLC connection and cyclic
I/O.
S5-95U, SINEC L2
EWA 4NEB 812 6112-02