Calculating The Local Cycle Time - Siemens SIMATIC CP 541 Manual

5.3.2

Calculating the Local Cycle Time

Introduction
Preconditions
Definitions
Communications Processor CP 541
EWA 4NEB 812 6188-02
The following is an explanation for calculating the local receive and send
cycle times for a connection between a CP 541 and a connected program-
mable controller.
The following preconditions apply to the calculation:
The send delay time (POL) must not be longer than the transit time of the
shortest send message, plus the transit time of the shortest receive mes-
sage.
The specially defined priority list must not contain duplications.
Note
The CP 541 receives broadcast messages from all the stations with the basic
settings in DB1. These broadcast messages contribute to the local cycle time.
Proceed as follows to ensure that broadcast messages which are not needed
will not be received:
If no broadcast is to be received, you must assign the value 0 to parame-
ter BSAP.
If broadcast messages are only to be received from certain L2 stations,
define your own priority list.
The following definitions apply to this section:
Receiving: Receiving is understood to mean the message direction from
the CP 541 to the connected programmable controller.
Sending: Sending is understood to mean the message direction from the
connected programmable controller to the CP 541.
CP 541 with S5-95F/S5-1 15F
5-11