Regarding Pulse width of the DO option module (with PM8240)

[T.Okada]

Hi,

We are using a digital output option module on the PM8000 with the following setup:

• Port A D1: DO output triggered by sag/swell detection (pulse width set to 40 ms)
• Port A D2: DO output triggered by a newly created setpoint for harmonic voltage detection (pulse width set to 100 ms)

Although we have definitively configured the output module (pulse width) to:

• 0.04 s
• 0.10 s

both channels operate correctly at the specified durations when the input pulse to the digital output module’s Force On is the sag/swell SS1 Dist Start.

However, when the input pulse to Force On is from the harmonic detection

(the pulse generated when the setpoint module threshold is exceeded),

both channels produce pulses of approximately 1 second.

It’s puzzling because both cases are pulse outputs.

Looking closely at the event log timestamps for the DO output,

when the pulse is triggered by harmonic detection,

the outputs occur at 1-second intervals rather than 0.1 seconds.

Do you know what might be causing this?

Ultimately, we want:

• For sag/swell detection (sag/swell module): a pulse width of 40 ms
• For harmonic detection (setpoint module): a pulse width of 100 ms

and for each to output correctly as configured.

Regards,

Okada

[Mehran_Mehrnia]

Hi @T.Okada 

The harmonic detection is derived from the Harmonics Measurement modules, which operate at a one-second update rate. According to the ION Reference, when a standard ION module is involved, the framework execution rate is limited by the slower module.

Since the Sag/Swell module is a High Speed module and the Harmonics Measurement module is a one-second module, harmonic-triggered outputs will naturally exhibit approximately one-second timing resolution, whereas sag/swell-triggered outputs can respond at high-speed rates. This explains the difference in the observed pulse behavior.

Best Regards,

-Mehran

L3 Expert Advanced metering

[Charles_Murison]

Hello @T.Okada ,

Are you able to provide some details about your framework? Ideal would be entire template but if that is not possible would be good to share Details about the inputs, including handles, and the setup registers.

Regards,

Charles

[T.Okada]

Hi @Mehran_Mehrnia, @Charles_Murison 

Thank you for your prompt response.
I’ve attached an image with the framework details.
Given this configuration, do you have any recommendations on how to implement a 100 ms pulse width for Over-THD detection?

For reference, “THD V1–V3 Max” and “THDV High Limit” are custom modules we developed.

Regards,

Okada

[Mehran_Mehrnia]

Hi @T.Okada 

You're welcome.

@Charles_Murison please correct me if I am mistaken, but as previously mentioned, this behavior is related to the module's execution speed. Since the Harmonics Module, which is the source of the signal, operates at a low-speed update rate of 1 second, any modules linked to its output will also operate at the same update rate.

I reproduced the same scenario shown in the image. Although the PulseWidth parameter is set to 0.1 second, the Event Log records the pulse duration as 1 second, as shown below. This occurs because the pulse is generated by a source module running at a 1-second update rate, which limits the effective resolution of the pulse timing.

Therefore, the observed behavior is expected and is a consequence of the source module's execution rate rather than the configured PulseWidth value.

ION Reference: Digital Output

Best Regards,

-Mehran

L3 Expert Advanced metering

[Charles_Murison · Accepted solution]

Hello @T.Okada 

Looking at the ION reference I can see the following note for Digital Output modules (ION Reference )
"Note: The pulse width is dependent on the operate period of the Digital Output Module. For example, if a Digital Output Module is operating at 1-second intervals, the pulse width will be a multiple of 1 s, rounded up from the value set in the PulseWidth register."

Digital output modules with be either 1/2 cycle or 1 second speed depending on the input(s). If all inputs are 1 second modules, the Digital output will be 1 second. If any input is high speed, module will be high speed.

One way to make this happen is to use a pulse merge module. The the pulse output from your setpoint module be one input to your pulse merge module then use a pulse output from a 1/2 cycle module. The pulse merge module will be 1/2 cycle so Digital output will be 1/2 cycle. 

Regards,

Charles

[Mehran_Mehrnia · Accepted solution]

Hi @T.Okada 

Here's a simple example implemented based on Charles's suggestion:

Best Regards,

-Mehran

L3 Expert Advanced metering

[T.Okada]

Hi @Mehran_Mehrnia , @Charles_Murison ,

Thank you for the idea.
I updated the framework based on your suggestion

(using a pulse merge and a high‑speed frequency module),

and the issue is resolved.

Regards,

Okada