Siemens SIMATIC PCS 7 Operating Manual page 155

T /T parameters
WCDT OFDT
Note
Whether errors are present or not, the maximum response times depend on the type of
module, and can be obtained from the following manuals:
• SIMATIC Automation System S7-300 ET 200M Distributed I/O Device Fail-safe Signal
Modules (https://support.industry.siemens.com/cs/ww/en/view/19026151)
• Distributed I/O Distributed I/O device ET 200iSP – Fail-safe Module
(https://support.industry.siemens.com/cs/ww/en/view/47357221)
F signal module
DI 24 x DC 24 V
6ES7326-1BK02-0AB0
DI 8 x NAMUR
6ES7326-1RF00-0AB0
6ES7326-1RF01-0AB0
F-DO 8 x DC 24V/2A PM
6ES7326-2BF40-0AB0
F-DO 8 x DC 24V/2A PM
6ES7326-2BF41-0AB0
DO 10 x DC 24V/2A
6ES7326-2BF01-0AB0
F-DO 10 x DC 24V/2A PP
6ES7326-2BF10-0AB0
AI 6 x 13Bit
6ES7336-1HE00-0AB0
F-AI 6 x 0/4 ... 20 mA HART
6ES7336-4GE00-0AB0
Compendium Part B - Process Safety (V8.2)
Operating Manual, 07/2016, A5E35031794-AB
T
WCDT
= Max. internal processing time + input
delay + short-circuit test time
= 23 ms + 3 ms + 6 ms = 32 ms
= Internal processing time + input delay
= 55 ms + 3 ms = 58 ms
If an error is present, the response time is extended by the configured discrepancy time, if
"1oo2 (2v2)- evaluation" of the sensors was configured.
= Max. internal processing time
=14 ms
= Max. internal processing time
=14 ms
= Internal processing time =24 ms
Max. response time = 2 × internal processing time + MAX{ Max. dark test readback time,
max. light test time } + 10 ms = 2 × 8 ms + MAX{ 1 ms, 0.6 ms } + 10 ms = 27 ms
= N × response time per activated channel + basic response time
E.g.: N = 6, interference frequency of 50 Hz
•
= 6 × 50 ms + 50 ms = 350 ms
E.g.: N = 6, interference frequency of 60 Hz
•
= 6 × 44 ms + 44 ms = 308 ms
If an error is present, the response time is extended by the configured discrepancy time, if "2
sensors" was configured and the signal does not have a secure failure direction (or the "unit
value" was not configured in accordance with this secure failure direction).
With 1oo1:
= 2 × conversion cycle time × filter
E.g.: interference frequency of 50 Hz,
•
filter = 1 conversion cycle, 3 active
channel pairs
= 2 × (3 x 25 ms + 50 ms) × 1
= 250 ms
Configuring the safety program
7.11 Monitoring times and system response times
T
OFDT
= 31 ms with 1oo1 evaluation
= 29 ms with 1oo2 evaluation
With parameter assignment: "Provide last
valid value", the set discrepancy time has to
be added.
= 2 × conversion cycle time
E.g.: interference frequency of 50 Hz,
3 active channel pairs
= 2 × (3 x 25 ms + 50 ms)
= 250 ms
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