Docklight Scripting – Simulating and Testing TCP/UDP Applications

Docklight Scripting is an extended edition of the Docklight RS232 Terminal / RS232 Monitor. It can establish TCP connections (TCP client mode), accept a TCP connection on a local port (TCP server mode), or act as a UDP peer.

Docklight Scripting is a great companion for debugging network-enabled devices and applications that use single endpoint-to-endpoint connections. You can easily simulate basic functions of your application layer protocol and use Docklight Scripting for:

  • Testing your server application without writing additional client software
  • Testing your client application with Docklight acting as server
  • Testing your application protocol before implementation

Docklight Scripting – Key Functions

Simulating application layer protocols
Docklight can send out user-defined sequences according to the protocol used and it can react to incoming sequences.

Developers of a server application can use Docklight Scripting as a test client.

Docklight Scripting TCP
Docklight Scripting TCP Modbus

Logging communication data
All communication data can be logged using two different file formats: use plain text format for fast logging and storing huge amounts of data. Or create a HTML file with styled text that lets you easily distinguish between incoming and outgoing data or additional information.

The screenshot on the left shows a MODBUS TCP session between Docklight and a Barionet network automation controller.

Detecting specific data sequences
In many test cases you will need to check for a specific sequence within the logged data that indicates a certain condition.

Docklight manages a list of such data sequences for you and is able to perform user-defined actions after detecting a sequence, e.g. inserting additional command descriptions as shown in the UDP communication example on the right.

Docklight Scripting UDP

Monitoring TCP connections
Docklight Scripting allows you to monitor and debug a TCP-based application with the same ease as when using RS232 ports and cables.

Instead of using a Docklight Monitoring Cable between the two devices being tested, you can run Docklight Scripting within the network and simply have the client connect to Docklight Scripting instead of the network-enabled product.

  • Device 1 - e.g. 192.0.0.3001
  • Docklight - e.g. 192.0.0.2
    Monitoring: Server 3001, 192.0.0.2
  • Device 2 - e.g. Server IP 192.0.0.1, TCP port 3001

Docklight Scripting – What it is not

Please note that Docklight Scripting is not a network protocol analyzer. It works on the application layer only, acting as a client or server within a network.

It is NOT a troubleshooting tool for network problems, like the well known Wireshark® (Ethereal®) network protocol analyzer.