# Comtrade Viewer — COMTRADE analog trace viewer.

> COMTRADE analog trace viewer. (iPhone/iPad app by Russell Patterson.)

- Source: https://appshunter.io/ios/app/comtrade-viewer/id1469713323 (this page in markdown: same URL + `.md`)
- Developer: [Russell Patterson](https://appshunter.io/developer/1723606459)
- Category: Utilities, Productivity
- Price: Free
- Age rating: 4+
- Requires: iOS 15.0 · 4 MB
- Languages: English
- Released: 2019-09-16
- Data updated: 2026-07-05
- User reviews in markdown: https://appshunter.io/ios/app/comtrade-viewer/id1469713323/reviews.md

## What is Comtrade Viewer?

COMTRADE Viewer is an easy-to-use tool for viewing and analyzing power system event records. Display waveforms directly on your device.

Supported file formats include:

• COMTRADE (ASCII and Binary)
• SEL .cev, .eve, and .evzip event records
• SEL Motor Start Reports (.msr and .cmsr)
• Beckwith M-3425A, M-3430, and M-3311A .osc records
• S&C IntelliRupter Fault Interrupter records (.wfc)
• ATP/EMTP .pl4 files

Open files directly from Mail, Files, AirDrop, and other supported apps, or explore the included sample records to get started.

Built for power system engineers and technicians who need quick access to event records while in the field, at the office, or on the go.


## Version history (last 5 releases)

### 2.2.3 — 2026-06-20

Added ability to open a zip file containing multiple records of any supported type. User then may select one of the records to view. This makes it convenient to group all related records in one compressed file that can be opened from mail or from the device storage.

### 2.2.2 — 2026-06-06

Minor user interface improvements. Added capability to open the following records:
• SEL .cev, .eve, and .evzip event records
• SEL Motor Start Reports (.msr and .cmsr)
• Beckwith M-3425A, M-3430, and M-3311A .osc records
• S&C IntelliRupter Fault Interrupter records (.wfc)
• ATP/EMTP .pl4 files

### 2.1.1 — 2026-05-25

- Fixed incorrect record duration seen when opening some SEL-735 generated event records.
- Added link from the app to detailed online help at comtradeviewer.org/help.html

### 2.1.0 — 2026-05-19

Voltage and current phasor diagrams, symmetrical components, and a full R-X impedance plane with loop impedances.

### 2.0.0 — 2026-05-12

Major update with iOS 26 support, refreshed interface, and new sample records.
• Rebuilt from the ground up for iOS 26
• Try the app without your own data — tap a sample record on the empty screen
• Open .cff, .osc, and .pl4 files directly from Files, Mail, or AirDrop
• Monochrome mode
• Email to Support now bundles your record files into a single zip attachment
• Many new settings to customize
• Gear icon for quick access to settings
• Dark mode and tinted app icon support

## Apps similar to Comtrade Viewer

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| --- | --- | --- | --- |
| [ScopeSnap](https://appshunter.io/ios/app/scopesnap/id6747386383) | — | Free | Utilities |
| [MAPIR SCANNER](https://appshunter.io/ios/app/mapir-scanner/id6745078935) | — | Free | Utilities |
| [CMC Swift](https://appshunter.io/ios/app/cmc-swift/id1498901607) | 5.0 (1) | Free | Utilities |
| [Power Welfare Organization](https://appshunter.io/ios/app/power-welfare-organization/id1375428737) | — | Free | Utilities |
| [Comsel Install](https://appshunter.io/ios/app/comsel-install/id1673366585) | — | Free | Utilities |
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## More apps by Russell Patterson

- [PSRC Agenda](https://appshunter.io/ios/app/psrc-agenda/id1376841558)
- [JTCM Agenda](https://appshunter.io/ios/app/jtcm-agenda/id1439235885)
- [PQDIF Viewer](https://appshunter.io/ios/app/pqdif-viewer/id6769140607)

All apps by Russell Patterson: https://appshunter.io/developer/1723606459

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-05.*