5-14
Communications Processor CP 541
EWA 4NEB 812 6188-02
5.3.3
Condition for the SINEC L1 Safety Time for Receiving
When planning a safety-related system, you and the inspector agree a pro-
cess-dependent SINEC L1 safety time for receiving.
When using the CP 541, you must verify the condition for the SINEC L1
safety time for receiving, according to a formula. Please note that you must
not use the standard formula for verification from the manuals of the S5-95F
and S5-115F programmable controllers.
Verify the SINEC L1 safety time for receiving on the basis of the formula
given below. All other conditions from the manuals of our S5-95F and
S5-115F programmable controllers still apply unchanged.
The formula for verifying the SINEC L1 safety time for receiving is:
SINEC L1 safety time for receiving
(2
t
LUS
)
t
L2
(2
t
LUE
)
Max. adjustable CP 541 safety time for receiving=(SINEC L1 safety time for receiving)–t
LUE
with:
t
LUS
local cycle time for sending by the sender
t
LUE
local cycle time for receiving by the recipient
t
L2
transmit time in SINEC L2
The following are valid for t
L2
:
L2 no. of stations
25: t
L2
100 ms
L2 no. of stations
25: t
L2
L2 no. of stations
4 ms
Shown in the following figure are the local cycle times for sending and re-
ceiving and the transit times for message transmission.
Sender
Recipient
CP
541
CP
541
t
LUS
t
LUS
t
L2
t
LUE
Shortest time which can be set with COM 95F/115F
Figure 5-3 Graphic Representation of Cycle Times
Introduction
Different Formula
Formulae
Graphic Represen-
tation of Cycle Ti-
mes
CP 541 with S5-95F/S5-115F