---
title: "devCat"
canonical: "https://m3mobile-manual.refined.site/space/M3APPMANUAL/128647170/devCat"
format: markdown
---
> Macro (ui-button)
devCat APP Manual Update History
`July 14, 2026`
- Updated the Log Viewer, Record, Send, and Settings sections based on the latest app behavior.
`November 19, 2025`
- Added information about what happens after log transmission.
`October 23, 2025`
- Updated the supported OS version information.
# **Supported devices**
| | | |
| --- | --- | --- |
| **Devices** | **About supported OS versions** | **App Icon** |
| **SM15** | Not supported |  |
| **SM20** | Android 11 or higher |
| **UL20** | Android 11 or higher |
| **US20** | Android 11 or higher |
| **US30** | Android 13 or higher |
| **SL10** | Not supported |
| **SL20** | Android 11 or higher |
| **SL20K** | Android 13 or higher |
| **SL20P** | Android 13 or higher |
| **PC10** | Android 13 or higher |
| **WD10** | Android 13 or higher |
| **SM30** | Android 14 or higher |
| **UL30** | Android 14 or higher |
| **SM24** | Android 16 or higher |
# **Overview**
devCat is a log viewer app designed to help customers** view, save, and transmit **logs from their devices. When an issue occurs on a device, customers can collect the relevant logs through devCat and **send them directly to the M3 Mobile headquarters server**. Based on the analyzed logs, the M3 Mobile technical support team can **identify the root cause of the issue** and take any necessary follow-up actions with the customer.
# **Main Features**
- **Log Viewer**
- View logs in real-time
- Supports log buffer and log level filtering
- **Log transfer**
- Direct transfer to devCat management server
- Supports both immediate and scheduled transfers
- **Log Recording & Storage**
- Automatically records logs from a user-defined start point
- Supports various saving options such as full log save and partial save
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# **Feature details**
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## 1. Quick Start
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> ** Log Record**
>
> - Tap the red circular **[Record]** button on the main screen to start collecting log files.
> - Logs are recorded starting from the moment the file is created.
>
> > ℹ️ devCat Log File Path
> > ℹ️
> > ℹ️ Local : Internal storage > Documents > devCat > Saved_logs
>
> | 1. **Select the [Record] Button** | 2. **Create a Log File to Record** |
> | --- | --- |
> |  |  |
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> ** Standard Log Transfer**
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> - Tap the blue circular **[SEND]** button on the main screen to send the collected logs.
> - After entering **User Name, Select File, and Issue**, tap the **[SEND]** button at the bottom to immediately transfer the logs.
>
> > ℹ️ For standard transfers, make sure the **Schedule a send** toggle is disabled.
> > ℹ️
> > ℹ️ (For scheduled transfers, refer to **[4. Log Transfer](https://m3-mobile.atlassian.net/wiki/spaces/M3APPMANUAL/pages/128647170/devCat#4.-Log-Transfer(SEND))**.)
> > ℹ️
> > ℹ️ Logs are sent only when connected to a network
>
> | 1. ** Select the [SEND] Button** | 2. **Enter User Name, Select File, and Issue, then Send** |
> | --- | --- |
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> ** Check Transfer Result**
> A system notification will confirm whether the log transfer was successful or failed.
## 2. Log Viewer
| | |
| --- | --- |
|  | **Log Viewer**
- `Play` (▶) / `Pause` (❚❚): Starts or pauses the log output in the log viewer.
- `Log Expand` (⌵): Expands the log entry to view its full content.
- `Log Viewer`: The main screen where you can view real-time logs.
- `Filter`: Filters logs by log level, tag, and display items to show only the logs you need. For detailed instructions, see "Logcat Filter Settings" below.
- `TAB`: Creates separate log tabs for each applied filter condition. Select a tab to switch between logs with different filter criteria.
- `Record` (Red circular button): Records the current log output to a file. For instructions on how to record, see "[3. Log Recording and Saving (Record).](https://m3-mobile.atlassian.net/wiki/spaces/M3APPMANUAL/pages/128647170/devCat#3.-Log-Recording-%26-Saving(Record))"
- `Send` (Blue circular button): Sends saved log files to the M3 server. For instructions on how to send, see "[4. Log Transfer(SEND)](https://m3-mobile.atlassian.net/wiki/spaces/M3APPMANUAL/pages/128647170/devCat#4.-Log-Transfer(SEND))." |
|  | **Logcat Filter Settings**
`The Logcat Filter Settings` screen allows you to configure the criteria applied to filter tabs.
- Log Level: Select the minimum log level to display from the log level dropdown menu (▼) at the top.
- `Filter tags for search`: Enter the tags you want to filter by in the input field. Press [OK] after entering a tag to add it to the filter criteria. You can add multiple tag criteria to view logs for specific tags only.
- Show Section: Select the log details you want to display in the filtered tab. Check the boxes next to Time Stamp, Process ID (PID), Thread ID (TID), Flag, Tag, or Message to show only the information you need on the screen.
- Applying Settings: Click [APPLY] when finished to create a new tab with the specified criteria. The new tab will display logs filtered based on your selected log level, tags, and display items. |
## 3. Log Recording & Saving(Record)
You can record logs in real time from the log viewer and save them in various ways depending on your needs. There are three available saving methods, each differing in what portion of the logs are stored.
** Saving Methods (3 types)**
The log saving feature is available from the options menu (`⋮`) in the top right corner
- **Save Partial**: Saves only the selected portion of the logs.
- **Save File**: Saves the raw logs currently collected in the log viewer to a file.
Even if you execute this from a specific filter tab (e.g., TAB1), it will save the original raw logs before any filters were applied, rather than just the filtered results.
- **Record**: Saves the logs collected from the moment recording starts until it is manually stopped or the scheduled recording time expires.
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| --- | --- |
|  | **Log Recording & Saving(Record)**
- Press the red circular **[Record]** button on the main screen to create a file for collection.
- When recording starts, the recording status is displayed above the FAB (Floating Action Button) in the bottom right corner of the screen.
- The status area shows the current log file name, file size, and elapsed time. While recording, the red Record button changes to a **Stop** button, which you can press to end the log recording.
- Logs are collected from the moment the file is created.
> ℹ️ devCat log file path
> ℹ️
> ℹ️ Local : Internal storage > Documents > devCat > Saved_logs |
| 
 | **Record Log Filter Settings**
- Press **[FILTER…] **on the Record Log screen to configure the criteria for the logs you want to save.
- Filter text**:** Enter the search criteria for the logs to be saved. Entering plain text will save only the logs that contain those characters. You can also specify Process ID, Thread ID, and Tag criteria using the prefixes `pid:`, `tid:`, and `tag:`.
- Log level**:** Select the minimum log level to save. For example, selecting Error will only save logs that are at the Error level or higher.
> ℹ️ This filter applies directly to the log files saved via Record. Unlike the Filter/TAB feature in the log viewer, it does not create a new tab on the screen. |
## 4. Log Transfer(SEND)
> ℹ️ The logs sent by the customer are securely transmitted to the M3 Mobile headquarters server. We are not shared externally and can only be accessed internally by M3 Mobile technical support personnel.
Log Transmission works in two ways depending on whether `[Schedule a send]` is enabled:
- **Standard Transfer**: With `[Schedule a send]` disabled, select a previously saved log file to send it immediately.
- **Scheduled Transfer**: With `[Schedule a send]` enabled, pressing the `[SEND]` button starts a new log recording. Once the scheduled time is reached, the recorded log file is automatically sent.
| | |
| --- | --- |
|  | **Log Transfer(SEND)**
- In the Log Transfer screen, you must enter the `User name`** **and `Issue` fields.
- Under the `Issue`** **field, select the app or the type of issue where the log occurred. The selected issue information will be delivered along with the transmitted log.
**4-1) Standard Send (Immediate Send)**
- With `[Schedule a send]` disabled, select `[Select File]`.
- Select a previously saved log file and press the `[SEND]` button to transmit the log file immediately.
- Standard Send is used when you need to immediately send a log file that you saved after an issue occurred.
**4-2) Scheduled Send**
- With `[Schedule a send]` enabled, fill in the `Date` and `Time` fields.
- Pressing the `[SEND]` button starts recording a new log file. When the set `Date` and `Time` are reached, the recording ends and the generated log file is automatically transmitted.
- Scheduled Send is used when you need to continuously collect logs up to a specific time and then send them.
- You do not select an existing log file for a Scheduled Send.
> ℹ️ You cannot select an existing log file during a Scheduled Send.
> ℹ️
> ℹ️ Scheduled Send cannot be used if a Record is already in progress.
> ℹ️ **Logs are sent only when connected to a network.**
> ℹ️
> ℹ️ If there is no internet connection when you press the send button, devCat will not execute the transmission immediately but will remain in a pending state. The transmission will automatically start once Wi-Fi or a mobile network is reconnected.
> ℹ️
> ℹ️ However, if the network connection drops after the upload has already started, the transmission may fail. In this case, you must reconnect to the network and resend the log. |
## 5. More Option
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| --- | --- |
|  | **More Option**
- [Save File] saves only the original log data. Logs filtered by level, tag, or keyword are not included.
- `Clear`: Deletes all logs and tabs displayed in the log viewer.
- `File Open`: Loads a previously saved log file into the log viewer.
- `Save Partial`: Saves a specific selected section of the logs from the log viewer into a new file.
- `Save File`: Saves the raw logs collected in TAB0 of the current log viewer to a file. Even if you execute this while a filter tab (such as TAB1) is selected, it will save the original raw logs from TAB0 instead of the filtered results. |
|  | **Save Partial**
Saves a specific selected section of logs from the log viewer into a new file.
- Selecting `[Save Partial]` will display a guide screen for the feature.
Select the first log line of the range you want to save, and then select the last log line.
The logs between the two selected lines will be targeted for saving.
- Check `[Don’t show again]` to hide this guide screen in the future.
- Once the log range is selected, the Save Log screen appears.
Enter a file name and press `[OK]` to save the selected log range as a file. |
|  | **Settings**
- `Text Size`: Selects the text size to display in the log viewer.
- `Expand by Default`: Sets whether to display log entries expanded by default.
- `Log Buffer(s)`: Selects the log buffers to collect in the log viewer and during Record. You can choose one or more from Main, Events, Radio, System, and Crash. Selecting multiple buffers will display and record logs from all chosen buffers together. The default options are Main, System, and Crash.
- `Write Period`: Sets how often logs are written to the file during a Record. Logs are saved to the file after the specified number of lines is reached. You can enter a value between 1 and 1,000. The default value is 200.
- `Log Display Limit`: Sets the maximum number of log lines to display in the log viewer. The configurable range is 1,000 to 100,000 lines, and the default value is 3,000. When opening a saved log file, only the last logs up to this specified limit will be displayed.
- `App version`: Displays the current version of the app. |