SC050-120 Dig Output Errors

[bryantmorris]

Hello all,

I'm having an issue on a SC050-120 where I keep getting a 136 status on the digital outputs when an output is turned on. The output gets the signal to turn on but .Digfeedback tells me the output is not on.

According to the status information in the API document, 136 tells me there is a overload (a short) and the internal voltage is out of range. When the output is turned on the status becomes 128, which tells me the internal voltage is out of range. When the controller is first powered up, some of the outputs jump to a 128 status without being commanded, while others will stay at 0 status until I give them an on command, then they error.

I believe this is a wiring problem as I'm getting the same issue on 2 new controllers, however it is happening on a range out outputs, including running coils and running relays. The multi-function outputs work ok.

Any help on what to look for in my wiring harness that could be breaking these SC controllers?

[niteRider]

I ran into something similar when I used the outputs of a controller to drive proportional valves that were wired in parallel to a override switch.  Transient voltage on the output put the pins in overload, especially when you would de-energize the valve coil with the override switch and the controller tried to take control.

Diodes on your outputs to stop feedback would probably do the trick for you, if you cannot find the source.  On my application, I put a block of code to keep the output @ 0 when a overload was detected.  Good luck...

[bryantmorris]

Correction to my previous post. This is a Safety FET issue that is being triggered without good reason. There is no short circuit but the FETs are triggered on both dig inputs and multi-function outputs very easily.

Anything I can do to stop them triggering in the software?

[Beezkneez]

bryantmorris,

Did you ever resolve this issue? I am running 7, SC050-120 controllers on a new application and the exact thing you explained is beginning to be a problem for myself. I am running the latest HWD for the SC050-120 (70156324v180.sys) and I have the "DisableSafeFet" signal set to false on all digouts. It happens at complete random, when the output is on I get a status code: 136. When the output is turned off the status code: 128. After a brief power cycle the problem goes away for a while.

Please note that the secondary processor is running the same HWD file as the primary.

 Jake

[Pankaj2020]

Any help related to this problem?

I am also facing exact same issue with these controller for Dig output.

[Tor]

Hi Pankaja2020,

I had a talk with a colleague of mine, and found out there is a problem with these outputs. Especially if you have a capacitor connected. This will give a voltage on the output pin when the DigOut is off, which cause the problem.   I'm not saying this is the issue you have, but there have been some cases coming in to the PLUS+1 Helpdesk about this.

One solution can be to just disable the output for a short period when the DigOut is shut off. (See the quick and simple code I did).
When the DigOut goes low, a negative transition. Disable the monitoring for 1-2 sec.

This output, DisableOutputSafetyMonitoring, was added to the HWD file pretty recent. So if you don't see it, please update the HWD file and the template. If you don't want to update the template, you can add the signal yourself, but read the API before you do it.

Have a nice day.

[Pankaj2020]

Hi Tor,

Thanks for you help.

Do you know which version of 'hwd' we should be using? We are using 70156325v210 which was latest.

Thanks,
Pankaj

[Tor]

Hi,

The 70156325v210 seems to be the latest SC050-120 HWD.

Good Luck

[Pankaj2020]

Hi Tor,

Nope this solution doesn't help.

Still problem & as someone mentioned above Its totally random & goes away with Power cycle.

Pankaj

[Beezkneez]

For our situation we learned that it was a safety layer failure due to high frequencies registering on input pins. After trying all recommended solutions and having unsuccessful results we removed all SC050 controllers from our equipment and replaced with MC050-110's. We have never had issues with the MC050's. We chose to use the SC050 controller in hopes of someday attaining SIL2 certification. After all the problems we had with the SC we reverted back to the MC controllers and haven't looked back.

[Tor]

Hi Pankaja2020 and TheTurfDude

@Pankaja2020
If you look at the "SafetyLayer.Failure" signal, what Bit is set?  If you get Bit 4, "ISR Monitor Error", then there is another thing you can try.
As TheTurfDude mantioned, the reason might be an interrupt on the input pin. So you can try to ground all the MFin, Bias = 1, and test if it makes any difference. And to be sure, ground the MFin pins to the chassis ground.

@TheTurfDude.
I understand that you have been in contact with Danfoss about this issue before. I will bring this up with the Hardware Engineers again, because the MC050 will probably not be on the market forever. And there need to be a solution for this problem when they go obsolete.


Have a nice day.

[Marbek_Elektronik]

I haven't read all above and I don't know if this helps.
But just a litle tip:

For long time I have had an Output, which doesn't switch.
And only if I put an AND in front of this output it works.
Just take the signal or constant and then an AND-Symbol (2 inputs parallel connected) und the output to the real output signal.

[Fredrick]

I am also facing the 136 status when trying to drive a 1.6A coil in a 12VDC system, an external diod across the load seams to work this far.
Will there be an fix for this in the future on the SC050-controllers?   

[Peterh]

Hi all, was running into the same issue when I saw this topic in the forum
when looking into the SC050-120 documentation I noticed to recover you need to toggle the DisableSafeFet output for 250 [ms] and did this with a combination of a off delay recommended by Tor.
added the interface for reference, hope this solution suits you all.