KB88826
Published: November 4, 2020
Revision: 2.0

Output of TPO with Percentage (Duty Cycle) Above 100% is Not Constantly On


Applies To:

Firmware for:

  • GRV-EPIC-PR1
  • GRV-R7-MM1001-10

Versions Affected:

GRV-EPIC-PR1: All versions prior to 3.0.0
GRV-R7-MM1001-10: All versions

Resolved In Version:

For GRV-EPIC-PR1: 3.0.0


Symptoms:

You may observe this issue with a GRV-R7-MM1001-10 or a GRV-EPIC-PR1 that has any of the following modules:

  • GRV-ODCSRC-24
  • GRV-ODCI-12
  • GRV-OAC-12
  • GRV-OACI-12

After setting the TPO's percentage (duty cycle) above 100%, you may see either of the following behaviors on the TPO digital output point:

  • Turns off and remains off.
  • Turns off after a short delay and occasionally turns on briefly before turning back off (behavior similar to a TPO with a small duty cycle). The duration of the on-time is dependent on the TPO's period and percentage.

The following examples show the incorrect behavior you may observe with specific values for period and percentage:

  • If you set a TPO with a 200% duty cycle:
    • If the TPO's period is 0.5 s, then the on-time is about 1 s and off-time is about 214.25 s.
    • If the TPO's period is 0.05 s, then the on-time is about 0.1 s and off-time is about 214.7 s.
    • If the TPO's period is 0.005 s, then the on-time is about 0.01 s and off-time is about 214.75 s.
  • If you set a TPO with a 101% duty cycle:
    • If the TPO's period is 0.5 s, then the on-time is about 0.5 s and the off-time is about 214.746 s.
    • If the TPO's period is 0.005 s, then the on-time is about 0.0055 s and off-time is about 214.748 s.
    • If the TPO's period is 0.05 s, then the TPO channel's output remains off with no on-time.

Workaround:

Do not set a TPO with a percentage (duty cycle) above 100%.

Resolution:

Opto 22 has resolved this issue and will include the fix in an upcoming release.

Questions?

Contact: Opto 22 Product Support.
Phone: 800-835-6786 or 951-695-3080
Email: support@opto22.com


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