<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: FTP Server File Count Sensor

The FTP Server File Count sensor logs in to a File Transfer Protocol (FTP) server and can monitor changes to files.

FTP Server File Count Sensor

FTP Server File Count Sensor

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

Sensor in Other Languages

  • Dutch: FTP Server File Aantal
  • French: Serveur FTP compteur de fichiers
  • German: FTP-Server Dateienanzahl
  • Japanese: FTP サーバーファイルカウント
  • Portuguese: Contagem de arquivos servidor FTP
  • Russian: Количество файлов на FTP-сервере
  • Simplified Chinese: FTP 服务器文件计数
  • Spanish: Número de archivos en servidor FTP


  • This sensor has a high performance impact. Use it with care. We recommend that you use no more than 200 sensors of this sensor type on each probe.
  • This sensor requires Microsoft .NET 4.7.2 or later on the probe system. If the sensor shows the error PE087, additionally install .NET 3.5 on the probe system.
  • This sensor supports the IPv6 protocol.
  • We recommend Windows Server 2012 R2 on the probe system for best performance of this sensor.

Detailed Requirements



.NET 4.7.2 or later

This sensor requires .NET 4.7.2 or later to be installed on the probe system (on every cluster node, if on a cluster probe).

i_round_redIf the framework is missing, you cannot create this sensor.

i_square_cyanFor more information, see the Knowledge Base: Which .NET version does PRTG require?

Add Sensor

The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the settings that are required to create the sensor. You can change nearly all settings on the sensor's Settings tab after creation.

Basic Sensor Settings

Click the Settings tab of a sensor to change its settings.

Basic Sensor Settings

Basic Sensor Settings



Sensor Name

Enter a name to identify the sensor.

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

i_round_blueThis setting is for your information only. You cannot change it.


Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.

i_round_blueIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

i_round_blueFor performance reasons, it can take some minutes until you can filter for new tags that you added.

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

  • ptfsensor


Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority (i_priority_1) to the highest priority (i_priority_5).

Sensor Settings

Sensor Settings

Sensor Settings



FTP Mode

Define the FTP connection mode that the sensor uses for the connection to the FTP server:

  • Active mode: If you cannot establish a connection, use the passive mode.

i_round_blueWe recommend that you use the default value.

  • Passive mode

Check Method

Define how to access the FTP server directory that this sensor monitors:

  • URL: The sensor uses a URL of an FTP server to access the target directory. Define the URL below.
  • Folder on parent device: The sensor uses the IP address or Domain Name System (DNS) name of the parent device and monitors a folder on this device. Define the folder below.


This setting is only visible if you select URL above. Enter the URL that this sensor checks. The URL can look like this:

i_round_redIf you use this method, this sensor does not use the IP Address/DNS Name of the parent device.

i_round_blueYou can add a port number to the URL by using a colon, for example

FTP Port

This setting is only visible if you select Folder on parent device above. Enter the number of the port to which this sensor connects. The default port is 21.

FTP Folder

This setting is only visible if you select Folder on parent device above. Enter the name of the folder on the parent device that this sensor monitors, for example upload.

Recurse Subfolders

This setting is only visible if you select Folder on parent device above. Define if the sensor additionally monitors the subfolders of the FTP folder:

  • Do not recurse subfolders: Only monitor the folder. Do not monitor its subfolders.
  • Monitor the folder and its subfolders (recursive): Monitor the folder and all of its subfolders.
    i_round_redIf you recurse subfolders in large directories that have a high number of branches, this may cause timeout errors or performance issues.

User Name

Enter the user name for the login to the FTP server. Enter a string.


Define the password for the login to the FTP server. Enter a string.

File Count

Define which files the sensor counts:

  • Total number of files: Always show the total number of all files in the folder.
  • Only new files: Only show the number of new files since the last scanning interval. You can define the frequency of sensor scans in section Scanning Interval.
    i_round_blueWith every scanning interval, the sensor considers any new files from the previous scanning interval to be old.

Connection Security

Define the security of the connection:

  • Do not use transport-level security: The sensor connects without connection security.
  • Enforce transport-level security: The sensor establishes the connection to the FTP server via Secure Sockets Layer (SSL)/Transport Layer Security (TLS) in explicit mode.

i_round_redThis sensor only supports SSL/TLS in explicit mode.

If Value Changes

Define what the sensor does when the sensor value changes:

  • Ignore changes (default): Take no action on change.
  • Trigger 'change' notification: Send an internal message indicating that the sensor value has changed. In combination with a change trigger, you can use this mechanism to trigger a notification whenever the sensor value changes.

Debug Options

Debug Options

Debug Options



Result Handling

Define what PRTG does with the sensor result:

  • Discard result: Do not store the sensor result.
  • Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID].txt and Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.

i_podThis option is not available when the sensor runs on the hosted probe of a PRTG Hosted Monitor instance.

i_round_blueIn a cluster, PRTG stores the result in the PRTG data directory of the master node.

Sensor Display

Sensor Display

Sensor Display



Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary below a channel gauge on the sensor's Overview tab.

Graph Type

Define how different channels are shown for this sensor:

  • Show channels independently (default): Show a graph for each channel.
  • Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic.
    i_round_redYou cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).

Stack Unit

This setting is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.

Inherited Settings

By default, all of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.

Scanning Interval

Scanning Interval

Scanning Interval

i_square_cyanFor more information, see section Root Group Settings, section Scanning Interval.

Schedules, Dependencies, and Maintenance Window

i_round_blueYou cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.

Schedules, Dependencies, and Maintenance Window

Schedules, Dependencies, and Maintenance Window

i_square_cyanFor more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.

Access Rights

Access Rights

Access Rights

i_square_cyanFor more information, see section Root Group Settings, section Access Rights.

Channel Unit Configuration

i_round_blueWhich channel units are available depends on the sensor type and the available parameters. If no configurable channels are available, this field shows No configurable channels.

Channel Unit Configuration

Channel Unit Configuration

i_square_cyanFor more information, see section Root Group Settings, section Channel Unit Configuration.

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.




In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status in percent.

Execution Time

The execution time in milliseconds (msec)


The number of files that are available in the directory listing

i_round_blueThis channel is the primary channel by default.


i_square_blueKnowledge Base

Which .NET version does PRTG require?

What security features does PRTG include?