USB erroneous disconnection

Hi all

I’m new to this forum so thanks in advance for your patience.

I’m using the Maestro 24 channel card to power servos for rotary gauges. The issue is I find each time I close the software programme (Prosim)
the USB connection is lost.

Unplugging and plugging back works but obviously this isn’t right. Any ideas as to why this may be happening and could it be Pololu Maestro related
or more an issue with my software programme?

Thank you in advance


Hello, ALW.

Can you tell me what you mean by “the USB connection is lost”? Also, where are you seeing an indication of this?



Yes in my software programme there is a list of hardware components that are connected to the PC. The connection to the Maestro
card-under the heading POLOLU-in this programme is not shown each time I start it.

I have to physically disconnect and reconnect the USB cable from the Maestro card before it reappears in this list.
Hope that makes sense!




Think I might have resolved the issue. Through trial and error I’ve noticed
the focus of the USB connection is on whichever programme is being configured.

Essentially it’s one programme or the other.

For example I’ll save a setting in Pololu control centre and once I’ve opened my software programme connection is lost to the Maestro card. At this point I
have to disconnect and reconnect the USB cable in order for the card to be recognised in the list mentioned in my earlier post.

When I’ve completed configuring in my software programme I will go back to the Pololu control centre to find the connection there is lost but all I have to do here is click on the
drop down menu at the top left of the control centre and so on and so on.

Is there a way to keep the connection to both programmes permanently active to avoid the practice of disconnect/reconnect each time I change a setting?



Hello, ALW.

In Windows, only one program can connect to the Maestro’s native USB interface at once. Your two programs will have to take turns. You can disconnect the Maestro Control Center from the Maestro by selecting “Not connected” in the upper-left drop-down box. I don’t know anything about ProSim, and if it doesn’t have a disconnection option you might have to close the entire program to get it to release its handle on the Maestro’s native USB interface.


Hi David

That explains it then! Thank you for your reply, at least I know for sure now.


Alan W