Vault specifications

The technical detail behind Vault 0.1: platform, protocols, storage, data out, security and what has been measured.

Platform
Windows 10 or 11, 64-bit. Runs as a Windows service (automatic start, restart on failure, pre-shutdown handling) or as a portable Vault.exe from a folder.
Install
5.5 MB setup program, an MSI for IT deployment, or a portable zip. No .NET runtime, Java or database to install.
OPC UA
Client with subscriptions of up to 500 monitored items each, server limits negotiated and reported, per-signal sampling rates, optional server-side deadband, browse-and-tick signal picker, reconnect with Republish recovery of lost notifications, source, server or local timestamps.
OPC UA security
None, Sign, Sign & Encrypt. Basic256Sha256, Aes128_Sha256_RsaOaep, Aes256_Sha256_RsaPss. Certificates trusted in both directions; user name and password stored encrypted by Windows (DPAPI).
Modbus TCP
Holding and input registers, coils and discrete inputs. Block reads of up to 125 registers; 16, 32 and 64-bit integers and floats in four word orders; scale and offset; unit IDs; poll groups; heartbeat staleness; register-map CSV import.
Capacity
No licence limit on signals. Tested at 3,000 signals at one second; collection and storage use 0.5–0.65 % of one CPU core at that rate.
Storage
Write-ahead log synced every second by default (configurable down to every batch). Lossless compressed chunks (delta-of-delta timestamps, XOR and decimal floats) in one file per day, week or month. Each sealed file is integrity-checked and hashed with SHA-256; each chunk carries a CRC-32.
Time and quality
UTC timestamps to the nanosecond and a quality code on every value; times are shown to people in local time.
Compression
None unless chosen per signal: on change, deadband (absolute or % of span) or swinging door. Gaps and quality changes are never compressed away.
Disk management
Warns at 80 % full, removes the oldest sealed files from 90 % down to 85 %, halts collection at 95 % with the gap marked. The last seven days are never removed.
Data out
Raw, aggregated (minimum, maximum, mean and count per interval) or interpolated. CSV, Parquet, PNG, PDF. HTTP/JSON API with a bearer token. Grafana JSON data source with gaps as nulls and events as annotations.
Alarms
High, low, rate, bad quality, stale and expression rules with hold time, hysteresis, severity and acknowledgement. Notification by SMTP e-mail through a site relay, HTTP webhook or a command.
Reports
PDF reports on request or on a daily, weekly or monthly schedule, with statistics, charts with gaps and limits, notes and events. Missed reports are made up after downtime.
Users and audit
Answers on the PC itself only until people are added. Viewer, operator and administrator roles; PBKDF2-hashed passwords; HttpOnly session cookies; brute-force braking; audit events for every sign-in and change. TLS through a reverse proxy.
Viewer
Any current browser. Desktop and tablet layouts, dark and light themes, kiosk mode. No client licence.
Backup
Scheduled backups with verified sealed files; restore refuses to run under a live Vault and verifies every file it copies.

Measured

From the evaluation builds. Conditions are given with each figure; how Vault is tested explains the methods.

DocumentVault test record
Release0.1 evaluation
Signalsup to 3,000 at 1 s
Status5 pass, 3 open
RefTestResultVerdict
T-01Hard kill under load400 crash-test runs against the real program, including 339 hard kills while collecting, starting and shutting down and 56 clean stops, each followed by a full check of every stored value0 acknowledged values lostWorst loss at a kill: 39 ms at a 20 ms log sync on an idle rig; 71 ms with another process loading the CPU. Linux test rig; process kills, not power cuts.PASS
T-02Worst-nightmare fault injectionA test server sending known values through a proxy that drops, stalls and corrupts traffic; full disks, bit rot, 140 kills, hostile queries0 wrong, 0 duplicated, 0 gaps unmarked2,942,223 values compared with what was sent. 26 defects found and fixed along the way.PASS
T-03Windows soak2,500 signals from a simulated battery site over OPC UA (security None), one Windows service6.9 days without a restart632 M samples collected in that run (1,058 a second on average). All 675 M samples in the eight day files decoded and checked against their hashes: 0 errors. Seven 30-second stalls caused by an OPC UA library fault were stored as marked gaps (99.96 % captured). The fix is verified in a proxy test; a soak re-run on the fixed build is still to do.PASS
T-04Load3,000 tags at one second, no deadband, release build0.5–0.65 % of one CPU core2.8 GHz Xeon core. About 0.6 GB a day of raw one-second data.PASS
T-05Year-long queryOne tag, a year of one-second data (31.5 million samples), read at one-day intervals0.09 sChunk summaries answer most of the query without decoding.PASS
T-06Real PLCsA real Siemens S7-1500 and a Phoenix Contact PLCnext, over OPC UA with Sign & Encrypt, on an evaluation tester's benchIn progressResults will be published here, dated, as they come in.OPEN
T-07Power cut on WindowsThe plug pulled on a Windows panel PC under load, five times, each followed by a full checkNot yet runProves the disk honours the log sync, which a process kill cannot.OPEN
T-0830-day soak3,000 signals at one second on the target panel PC, tracking memory, handles and diskNot yet runOPEN
Figures from Vault 0.1 evaluation builds, September 2026. The crash, fault, load and reconnect tests ran on a Linux test rig; the soak ran on Windows. Open tests stay listed until they pass.

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