Overview
Part 11 compliance mode is a single master switch that enforces the strict record and signature controls required by 21 CFR Part 11 for regulated deployments. The switch is the Enable Part 11 Compliance Mode setting in the Part 11 Compliance (21 CFR) section on the Parameters page. Only users in the Administrators group can access the Parameters page.
Audit trail recording is always active, regardless of this setting. Compliance mode only controls the enforcement behaviors described below, so a system that runs without compliance mode still builds a complete audit trail from first startup.
Enforced Behaviors
Enabling Part 11 compliance mode enforces the following behaviors immediately, without a restart.
| Behavior | Description |
|---|---|
| Guest login disabled | A configured Guest HomePage is ignored and every session requires an individual login. A shared, passwordless identity would defeat the requirement that every recorded action is attributable to one person. When a Guest HomePage is configured while compliance mode is active, the Parameters page shows a warning that Guest login is disabled by Part 11 compliance mode. |
| Historic record deletion disabled | Delete actions on historic alarm and event records are refused with the message Disabled in Part 11 compliance mode. This applies to all users, including Administrators and users that hold the alarm or event delete rights. The Delete button on the Audit Trail page, which lets an Administrator clear the audit trail outside compliance mode, is locked in the same way, so enabling the mode also locks audit trail clearing. |
| Electronic signatures enforced | Actions selected under Signature Required Actions require an electronic signature before they execute. Write variables marked Signature Required applies to the variables that have Signature Required selected. See the Electronic Signatures article for the signing flow and the available action categories. |
| Mandatory password expiry | When Password Expiry (days) is set to 0 (unlimited), compliance mode applies a mandatory expiry of 90 days so passwords always age. A configured expiry value above 0 is used as-is. |
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Disabling Compliance Mode
Disabling Part 11 compliance mode always requires an electronic signature, independent of the Signature Required Actions selection. When the Enable Part 11 Compliance Mode checkbox is cleared, the Electronic Signature dialog opens and the change is only applied after a valid signature. The change itself, including the linked signature, is recorded in the audit trail, so compliance mode can never be switched off silently. The same signature is required when the setting is changed through the configuration API or MCP.
This implicit rule is shown in the Signature Required Actions list as the permanently selected entry Disable Part 11 compliance mode. It is the one configuration change that requires a signature; all other configuration changes are recorded in the audit trail without one.
Settings
The Part 11 Compliance (21 CFR) section on the Parameters page contains the following settings. Changes apply immediately.
The audit trail rotates on its own Audit Retention Days setting in the Historian section on the Parameters page, separate from Rotation Days. In a regulated deployment, size Audit Retention Days to at least the record retention period mandated for the application, or set it to 0 to retain the audit trail indefinitely. See the Audit Trail article for the rotation behavior.
| Setting | Description | Default |
|---|---|---|
| Enable Part 11 Compliance Mode | Master switch for the enforcement behaviors listed above. | Disabled |
| Signature Required Actions | Checkboxes that select which operator actions require an electronic signature while compliance mode is enabled: Download recipes to the process, Write variables marked Signature Required, Acknowledge alarms and events, Shelve alarms, Edit schedules in the Scheduler, and Restart devices. Each entry shows its action key in brackets. The Disable Part 11 compliance mode entry is always selected and cannot be cleared. | None selected |
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User Account Practice
Audit trail records identify the acting person by user name. To keep the recorded history attributable to one individual over the full retention period, assign each person an individual account and keep the user name unique to that person. When a person leaves the organization, retire the account and create a new account for their successor instead of renaming or reusing the existing one. The 21 CFR Part 11 Deployment Guide article covers the related procedural controls.