Page 1 of 1
PROFIsafe Watchdog tolerance
Posted: 26 Nov 2024, 10:44
by Booster
The PROFIsafe Tests include tests with the Safetylayer-Tester.
In documentation of Safetylayer-Tester, the watchdog test is required for certification.
It should be checked whether the measured times are within tolerance.
Maximum value = ((watchdog value + 10%) + device cycle time + inaccuracy of
measurement)
Does the Device-Cycle-Time correspond to the Device-Acknowledgment-Time?
Or does one of these times also include other times such as the transmission time?
Re: PROFIsafe Watchdog tolerance
Posted: 27 Nov 2024, 13:46
by DanielS
Booster wrote: ↑26 Nov 2024, 10:44
The PROFIsafe Tests include tests with the Safetylayer-Tester.
In documentation of Safetylayer-Tester, the watchdog test is required for certification.
It should be checked whether the measured times are within tolerance.
Maximum value = ((watchdog value + 10%) + device cycle time + inaccuracy of
measurement)
Does the Device-Cycle-Time correspond to the Device-Acknowledgment-Time?
Or does one of these times also include other times such as the transmission time?
Hi Booster,
no these are two different Times. The Device-Cycle-Time is the cycle time the time the device communicates with the F-Host e.g. 1ms. The Device-Acknowledgment-Time is the time the device needs to react on a changed MonitoringNumber (MNR). There is no other time included such as transmission transmission time.
BR
Daniel
Re: PROFIsafe Watchdog tolerance
Posted: 27 Nov 2024, 16:41
by Booster
DanielS wrote: ↑27 Nov 2024, 13:46
Booster wrote: ↑26 Nov 2024, 10:44
The PROFIsafe Tests include tests with the Safetylayer-Tester.
In documentation of Safetylayer-Tester, the watchdog test is required for certification.
It should be checked whether the measured times are within tolerance.
Maximum value = ((watchdog value + 10%) + device cycle time + inaccuracy of
measurement)
Does the Device-Cycle-Time correspond to the Device-Acknowledgment-Time?
Or does one of these times also include other times such as the transmission time?
Hi Booster,
no these are two different Times. The Device-Cycle-Time is the cycle time the time the device communicates with the F-Host e.g. 1ms. The Device-Acknowledgment-Time is the time the device needs to react on a changed MonitoringNumber (MNR). There is no other time included such as transmission transmission time.
BR
Daniel
Hey Daniel,
thank you for your answer!
How are the wd_min and wd_max values measured in detail?
Is the watchdog started and then monitored cyclically to determine whether it has been triggered? (wd_max)
And how is the wd_min value measured?
Thank you very much in advance for your answer!
Re: PROFIsafe Watchdog tolerance
Posted: 28 Nov 2024, 12:47
by DanielS
Booster wrote: ↑27 Nov 2024, 16:41
DanielS wrote: ↑27 Nov 2024, 13:46
Booster wrote: ↑26 Nov 2024, 10:44
The PROFIsafe Tests include tests with the Safetylayer-Tester.
In documentation of Safetylayer-Tester, the watchdog test is required for certification.
It should be checked whether the measured times are within tolerance.
Maximum value = ((watchdog value + 10%) + device cycle time + inaccuracy of
measurement)
Does the Device-Cycle-Time correspond to the Device-Acknowledgment-Time?
Or does one of these times also include other times such as the transmission time?
Hi Booster,
no these are two different Times. The Device-Cycle-Time is the cycle time the time the device communicates with the F-Host e.g. 1ms. The Device-Acknowledgment-Time is the time the device needs to react on a changed MonitoringNumber (MNR). There is no other time included such as transmission transmission time.
BR
Daniel
Hey Daniel,
thank you for your answer!
How are the wd_min and wd_max values measured in detail?
Is the watchdog started and then monitored cyclically to determine whether it has been triggered? (wd_max)
And how is the wd_min value measured?
Thank you very much in advance for your answer!
Hi Booster,
no these are two different Times. The Device-Cycle-Time is the cycle time the time the device communicates with the F-Host e.g. 1ms. The Device-Acknowledgment-Time is the time the device needs to react on a changed MonitoringNumber (MNR). There is no other time included such as transmission transmission time.
BR
Daniel
Re: PROFIsafe Watchdog tolerance
Posted: 02 Dec 2024, 09:24
by DanielS
DanielS wrote: ↑28 Nov 2024, 12:47
Booster wrote: ↑27 Nov 2024, 16:41
Hi Booster,
no these are two different Times. The Device-Cycle-Time is the cycle time the time the device communicates with the F-Host e.g. 1ms. The Device-Acknowledgment-Time is the time the device needs to react on a changed MonitoringNumber (MNR). There is no other time included such as transmission transmission time.
BR
Daniel
Hey Daniel,
thank you for your answer!
How are the wd_min and wd_max values measured in detail?
Is the watchdog started and then monitored cyclically to determine whether it has been triggered? (wd_max)
And how is the wd_min value measured?
Thank you very much in advance for your answer!
Hi Booster,
the layer tester establishes a connection to the device and starts safety data exchange. At a specific point the togglebit is not changed anymore and this results in a F_WD_Timeout. This happens a few times and the tester is calculating the time between stop changing togglebit and the change in the StatusByte from the device when it realizes the Timeout. Now you have a few measurements where you got a min and a max value.
Best regards,
Daniel