About CAS Modbus Scanner:

CAS Modbus Scanner is a free utility that allows communication with your Modbus devices. You can communicate through both TCP and Serial with your TCP/RTU Modbus devices, as the tool allows multiple connections running at the same time.


With the Modbus Scanner you can retrieve coils, inputs, holding registers, and input registers from a Modbus enabled device. Values retrieved from the device can be viewed in many different formats including Binary, Hexadecimal, Uint16, Int16, Uint32, Int32, and Float32.


You can easily schedule write tasks for writing into your Modbus device’s coils and holding registers.

System Requirements:

  • Windows 2000, XP (and above)
  • 10MB of free space
  • Serial/USB port (USB port would require a USB to Serial converter cable depending on your device)

Frequently Asked Questions (FAQ):

How do I add a new connection?

You can add a new connection by going to File>Settings>Add Task and clicking the Add Connection button.

I’m trying to add a device/request/write and I keep getting a “Please select a connection/device” error. What do I do?

When adding a device, you must highlight the connection you want to add the device under from the list of connections. The same goes for adding new requests or writes; you must highlight the device you want to add to first.

Where can I find a log of my session after I’ve closed my connections?

The log.txt file can be found in your base installation folder.

How can I suggest a new feature that I’d like to see in future updates?

You can suggest new features by e-mailing us directly. We will take all suggestions into consideration.