tia-sivarc

tia-sivarc

Scope

Use this skill for SiVArc engineering through the V21 C# Openness API.

• Assembly: Siemens.Engineering.Sivarc.dll
• Namespace: Siemens.Engineering.SiVArc (the namespace capitalization differs from the assembly filename)
• Entry point: Sivarc sivarc = project.GetService<Sivarc>()
• Prerequisite: load tia-csharp-common first

Do not substitute WinCC/HMI APIs for SiVArc rule or generation APIs. SiVArc generation creates, updates, renames, and may remove generated HMI objects; it is a live project mutation, not a read-only build step.

Reference files

Load only the reference required by the task.

Reference	Use for
references/generation.md	SiVArc license and generation preflight; exact GenerationOptions; result and recursive message handling
references/rules-and-libraries.md	All six rule families; tables, folders, groups, rules; library copies, type instances, and dynamic device columns
references/definitions-expression-layout.md	Tag/text definitions, tag member settings, definition upgrade, expression resolution, and screen layout YML import/export
references/api-catalogue.md	Complete inventory of all 92 installed V21 public SiVArc types

V21 service acquisition

using Siemens.Engineering;
using Siemens.Engineering.SiVArc;

Sivarc sivarc = project.GetService<Sivarc>();
if (sivarc == null)
    throw new InvalidOperationException("SiVArc is unavailable for the selected project or installation.");

Any modification of SiVArc data, including generation, requires a valid SiVArc license. V21 reports a missing license as a recoverable LicenseNotFound exception; do not convert that into a successful no-op.

Safety boundary

• Require explicit authorization for the exact project, HMI runtime/device names, PLC device names, rule objects, generation options, and mutation type.
• Resolve every table, folder, group, rule, block, screen, and library item by an exact selector. Fail on zero or ambiguous matches; never use .First(), index zero, or a silent fallback to a default table.
• Before generation, inventory the HMI-to-PLC connections, source PLC compile status, previous/frozen generation selection, rules included by the selected flags, and generated objects that may be replaced or removed.
• GenerationOptions.None means “use project settings”; it is not a preview or dry run. CreateOptions.Replace can overwrite an existing object.
• Imports, rule expressions, dynamic attribute names, library objects, and YML files are untrusted engineering input. Validate path, provenance, identity, and destination.
• Inspect returned result objects and recursive feedback. Exceptions and error counts fail the operation. Never infer success from a non-null return value.
• Do not claim generation rollback from a transaction without live V21 evidence. Use ExclusiveAccess for mutations and only use a transaction for calls proven compatible with it.
• Do not save the project unless persistence was explicitly requested. If validation fails, leave the project unsaved and report that live recovery/rollback was not proven.