I am looking at collecting data from many sensors. How many USB-1808s can be connected to a single PC? How about the software? If I develop my own application using the Universal Library, are there any limitations to the number of USB-1808s can be connected?
- Job Title: Engineer
- Industry: Automation
- Application: Data collection from sensors
40 months ago
AlfredL
South East Asia
Answers
Our Universal Library imposes no limits in terms of the number of USB devices that are supported. A USB host controller can enumerate up to 127 USB devices. The main limiting factor is going to be the USB bus bandwidth. Each USB device takes up a certain amount of bandwidth. When sampling data from multiple devices at high sample rates the bandwidth can easily be exceeded. The faster you sample the more bandwidth is used. Unfortunately, there is no accurate way calculate how many MCC DAQ devices can be used at full speed without exceeding the USB bus bandwidth. It all comes down to the sample rate of ALL the connected DAQ devices. If you exceed the bus bandwidth and our driver cannot keep up with the data transfer, you will in turn receive an “Overrun” error. An overrun error states that data was lost because the computer (bus bandwidth) could not keep up with the DAQs sample rate. Lowering your sample rate can alleviate this error and allow for additional USB DAQ devices to be connected. Your PC may also have multiple USB host controllers, allowing for more MCC DAQ devices if you connect them to different host controller ports.
40 months ago
Measurement Computing
Was this answer helpful?
Yes (1) /
No
(0)