Troubleshoot by symptom | Mingcedar

<div class="manual-doc-article manual-doc-article-section"><h2 id="common-issues">User guide: Troubleshoot by symptom</h2>

Diagnose using the affected page, update times, device quality and event records.

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<h3 id="common-issues-item-1">The page opens but values are unavailable</h3>

<p>Page access, realtime connection, PLC connectivity and Tag quality describe different stages.</p>

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<li>Check services and data infrastructure in System Status, then inspect device connection and collection in Devices.</li>

<li>Add the target Tag in Tag Diagnostics and check enabled state, address, type, quality and timestamp.</li>

<li>If the Tag is valid but the screen remains empty, check page references, the current release, menu target and page permissions.</li>

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<h3 id="common-issues-item-2">Remote data, alarms or trends are unavailable</h3>

<p>Inspect the remote site in the local Sites page.</p>

<ol>

<li>Check the remote address, connection identity, selected capabilities and device scope.</li>

<li>Open remote screens, alarms or trends separately to distinguish a connection failure from an unavailable capability.</li>

<li>Local rules using remote Tags also require local definitions and service input scope. A visible device catalog does not enable every consumer.</li>

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<h3 id="common-issues-item-3">Historical curves are empty or have gaps</h3>

<p>Historical queries depend on archiving and records actually saved within the selected period.</p>

<ol>

<li>Check the time range, timezone, device filter and selected series.</li>

<li>Check Tag archiving, sampling mode and interval, followed by Trend service status and retention.</li>

<li>Invalid quality or unavailable collection can leave no valid points. Gaps reflect recorded data; a wider interval can help locate the affected period.</li>

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<h3 id="common-issues-item-4">A write result is unconfirmed</h3>

<p>Acceptance, protocol completion and readback confirmation are different outcomes.</p>

<ol>

<li>Retain the request ID, timestamp, target and returned status, then find the operation in Event Records.</li>

<li>Inspect subsequent quality and values in Tag Diagnostics. Other operations may change the value, so compare timestamps.</li>

<li>If the outcome remains unknown, reconcile device state and request records before repeating an operation.</li>

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<h3 id="common-issues-item-5">Scripts or external APIs are unavailable</h3>

<p>Developer interfaces and administration pages have distinct permissions and runtime prerequisites.</p>

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<li>For Python, check the Script service, active project version, enabled events and actions, and run records. After adding a dependency, confirm the installation result and check its import in the same project.</li>

<li>For IO State API, check published Profile revision, Access Key, scopes and signal range. A connection ticket is single-use.</li>

<li>For the page SDK, check that the screen is opened through a host menu, its declared reads/writes and user permissions. Use the relevant chapter’s errors and status descriptions.</li>

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