Q: Right now, I have one Cheetah SPI Host Adapter hooked up and it is working great. I am looking into using two Cheetah adapters on the same PC. I have some questions:

1. Can two Cheetah adapterss work on the same PC?
2. How would I address each Cheetah adapter separately?

Also, I am using my own API.

A: Thanks for your question! Yes, you can connect two (or more) Cheetah SPI Host Adapters to one computer, one Cheetah adapter per USB port. You will need to identify the Cheetah adapters on your computer by their serial numbers as well as the ports to which they are connected. Here is an outline of the commands to add to your API.

1. Perform the ch_port command for the Cheetah-1 handle: get this port number.
2. Perform the ch_port command for the Cheetah-2 handle: get this port number.
3. Perform the ch_unique_id command for the Cheetah-1 handle: get this serial number.
4. Perform the ch_unique_id command for the Cheetah-2 handle: get this serial number.
5. Perform the rest of the commands using the Cheetah-1 handle.
6. Perform the rest of the commands using the Cheetah-2 handle.

The port numbers and the serial numbers identify the physical device in the API software that you use. For more information about Cheetah API, refer to section 5 of the Cheetah SPI Host Adapter Data Sheet.

Figure 1: Cheetah SPI Host Adapter

Additional information is available on our web site, including the following:

There are examples of royalty-free Cheetah Software API that you can download and use. We provide a software API (32-bit and 64-bit) for C, C#, Python, .NET, VB.NET, and VB6, as well as a Cheetah LabVIEW driver for Windows, all at no charge.

In addition to API, there are the Cheetah GUI software application and the Cheetah GUI User's Manual, which you can download from Cheetah GUI Software. You can use the Cheetah GUI software to set up multiple Cheetah handles on one computer, as well as run all Cheetah SPI host adapter functions and view, filter and log transactions.

We hope this answers your question. If you have other questions about our Total Phase products, feel free to email us at sales@totalphase.com or support@totalphase.com.