B-3
Communications Processor CP 541
EWA 4NEB 812 6188-02
Here are two examples of a priority list.
PRI 1, 6, 2
Stations 1, 6 and 2 will always be interrogated successively. Each station
has the same priority. Messages from other stations will not be trans-
mitted.
PRI 1, 6, 1, 2
With each cycle, Station 1 will be interrogated twice. Station 1 thus has a
higher priority. Messages from other stations will not be transmitted.
When the message-oriented communication modes PLC-PLC connection and
broadcast are used, the CP 541 must be assigned a parameter as the active
station (STA = AKT). In this case, the CP 541 must receive the send autho-
rization within the token rotation time.
The greater the number of active stations in SINEC L2, the greater is the
time required for token management of all active stations.
You can optimize parameter STA as follows:
If you only wish to use the DP connection, you can assign a parameter to the
CP 541 as the passive station (STA = PAS). The token rotation time will thus
be reduced and SINEC L2 will only be loaded with data transmission.
Parameter UPDL affects data transmission from the CP 541 to the connected
programmable controller. With the default setting, it is intended for the
S5-95F and S5-115F. UPDL is preset with 100 ms (UPDL = 10) for these two
SIMATIC S5 controllers.
With a reduction in this value, successive messages can be sent more fre-
quently from the CP 541 to the connected programmable controller.
You can optimize parameter UPDL as follows. Observe the defaults of your
connected programmable controller, especially with the S5-95F and S5-115F
(see Sections 5.3.1 to 5.3.5).
If your programmable controller can process a subsequent message after a
receive message after a shorter time, you can reduce the value of UPDL.
Note that more frequent sending to the connected programmable control-
ler results in its being subjected to a higher basic load for interface pro-
cessing.
If incoming messages from SINEC L2 can be sent to the connected pro-
grammable controller without delay, you can assign the value 0 to UPDL.
Example
Parameter STA
Optimization
Parameter UPDL
Optimization
Optimizing SINEC L2
