Siemens SIMATIC CP 541 Manual page 56

CP 541 with S5-95F/S5-1 15F
Node 2
Local Cycle Time
for Sending STN 2
Local Cycle Time
for Receiving
STN 2
5-20
Calculation of local cycle times:
Two receive messages and one send message are present. The message
transit times are given by:
– Sending of 10+4 bytes to Station 1: 14 2 ms + 44 ms = 72 ms
– Receiving of 20+4 bytes from Station 1:
24 2 ms + 44 ms = 92 ms
– Receiving of 12 bytes from Station 3:
12 2 ms + 44 ms = 68 ms
Messages sorted according to size:
– Sending: 72 ms
– Receiving: 92 ms, 68 ms
Verification of conditions for the send delay time:
POL shortest send message + shortest receive message
POL = 100 ms (default setting in DB1) 72 ms + 68 ms = 140 ms
You obtain the local cycle time for sending by adding the individual values.
Sending 72 ms
Receiving 92 ms
*
Receive message is deleted.
You obtain the local cycle time for receiving by adding the individual values.
Receiving 92 ms
Sending 72 ms
*
Send message is filled in.
(72 + 92) ms (
*
68 ms
= 164 ms
68 ms
( (92 + 68 + 72 + 72) ms
*
72 ms
= 304 ms
Communications Processor CP 541
EWA 4NEB 812 6188-02
)
)