Author Topic: SC050 Safety FET  (Read 5740 times)

Offline jashom1

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SC050 Safety FET
« on: June 03, 2016, 01:25:27 AM »
Hello Gurus,

Just wondering if anyone has had any experience with SC050 and false tripping of the Safety FET on an output.

I am having issues driving proportional solenoids where when they are turned off quickly that the Safety FET disabled is flagged, and no output is able to function until I toggle the DisableSafeFET on the output that failed.

I have replaced wires to the SC050 ground, to the solenoid, and grounded the solenoid to the same point as the SC050 ground.  Also tried back EMF diode across the coil but nothing seems to make any difference.

I have tried changing the SC050 which shifted the problem to another solenoid output so I am thinking it maybe firmware related.

I have contacted the helpdesk, but I was wondering if anyone else has had similar issues and how did they get around it.

Thanks for your help.

John.

Offline bryantmorris

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Re: SC050 Safety FET
« Reply #1 on: February 19, 2018, 11:25:10 PM »
Hi Jashom1,

I'm having the exact same issue on a SC050 controller on an application at the moment.

The Safety FETs are engaging without good reason. Did you get a solution to this? Is there a way to disable the safety fet protection?

Offline jashom1

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Re: SC050 Safety FET
« Reply #2 on: February 20, 2018, 02:21:07 AM »
Hi Bryantmorris,

My issue has been resolved by the helpdesk, it ended up being an update to the firmware plus I had to disable current decay rate monitoring.  Decay rate monitoring monitors the rate in which the output current drops, and if it doesn't drop within the required time then this Safety FET failure condition is reported.

Are you using the latest template? The firmware I am using is SYS 70156324V170

I had to add into each hardware output eg: "C1p39.DisableCurrentDecayRateMonitoring" as a hardware input and set it to true.  This will deactivate it for that pin, though it only works for multifunction output pins, not digital outputs.

The helpdesk cautioned me that I had to implement my own current decay rate monitoring if used for a safety control function.

Hope this helps.

John.

Offline FStelzer

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Re: SC050 Safety FET
« Reply #3 on: February 20, 2018, 05:24:50 PM »
Hi,

I had the same issue once.

Do you have already an application on the secondary processor ? If not or you don't use the secondary, you have to download an empty software on it. Also use the latest .hwd file for primary and secondary.

If this doesn't work, jashom1 already write that you should disable the current decay rate monitoring.

Offline bryantmorris

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Re: SC050 Safety FET
« Reply #4 on: February 21, 2018, 06:10:16 AM »
Hi all,

Thank you for your comments. I'm currently using the 70156324v170.sys for the SC050-120.

I can try disabling the .DisableCurrentDecayRateMonitoring but this would not help the issue on the DigOut outputs as they don't include the ability to do this.

I have also installed a blank copy of 70156321v170.sys for the SC050. This helped some of the issues I was experiencing but has not solved all of the Fet errors, specially on the Digital outputs.

Offline FStelzer

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Re: SC050 Safety FET
« Reply #5 on: February 21, 2018, 07:18:29 AM »
Hi,

what are you controlling with the DigOut ? Do you already tried to put in a relay ?

In the past I had also some problems with controlling a signal horn which was going periodically ON and OFF. There I also got the SafetyFET error on the output pin. After putting in a relay, the problem was solved.


Regards,
FStelzer