USB Latency generator

[jannievanzyl]

/Hope this is in the right sub-forum

Looking for a "black box" solution that will introduce a configurable latency between an USB host and device. Something that's "plug-and-play". I'm doing it today with a PC and a fair amount of software but really needs something that's idiot-proof. (Something like an RPI with relevant software on it. )

I thought it'd be readily available but can't find something like it, suspect not so easy at a low level to introduce latency?

Any ideas, or anyone that could develop something like this?

 

[netstrider]

/Hope this is in the right sub-forum

Looking for a "black box" solution that will introduce a configurable latency between an USB host and device. Something that's "plug-and-play". I'm doing it today with a PC and a fair amount of software but really needs something that's idiot-proof. (Something like an RPI with relevant software on it. )

I thought it'd be readily available but can't find something like it, suspect not so easy at a low level to introduce latency?

Any ideas, or anyone that could develop something like this?

Not entirely sure if I understand you correctly. Is this the direction you are leaning toward?

https://tldp.org/HOWTO/Traffic-Control-HOWTO/components.html

 

[|tera|]

/Hope this is in the right sub-forum

Looking for a "black box" solution that will introduce a configurable latency between an USB host and device. Something that's "plug-and-play". I'm doing it today with a PC and a fair amount of software but really needs something that's idiot-proof. (Something like an RPI with relevant software on it. )

I thought it'd be readily available but can't find something like it, suspect not so easy at a low level to introduce latency?

Any ideas, or anyone that could develop something like this?

Easier method.
Use different lengths of USB cables.
Longer cables, increased latency.
Shorter, less latency. Just an idea.

 

[netstrider]

Also found this, not sure how well it works.

WANem - Wide Area Network Emulator

Download WANem - Wide Area Network Emulator for free. Wide Area Network Emulator. WANem is a wide area network emulator. It supports various features such a bandwidth limitation, latency, packet loss, network disconnection among other wide area network characteristics.

sourceforge.net

 

[jannievanzyl]

Also found this, not sure how well it works.

WANem - Wide Area Network Emulator

Download WANem - Wide Area Network Emulator for free. Wide Area Network Emulator. WANem is a wide area network emulator. It supports various features such a bandwidth limitation, latency, packet loss, network disconnection among other wide area network characteristics.

sourceforge.net

This is the concept (and I use some of these for IP networks) but looking for one that does latency insertion in an USB link.

As a practical example, I want to unplug my USB mouse from my PC and plug this box inline, i.e. the mouse goes into the box and a cable from the box into the PC. Now the box must be able to insert a latency in one direction, say up to 100ms.

The practical effect is to show how a small latency affect HMI (human machine interfaces).

Makes sense?

 

[jannievanzyl]

Easier method.
Use different lengths of USB cables.
Longer cables, increased latency.
Shorter, less latency. Just an idea.

Going to need a moer-of-a-long cable

No, I need tens of milliseconds, so a cable won't work. Will need to be something intelligent.

 

[netstrider]

This is the concept (and I use some of these for IP networks) but looking for one that does latency insertion in an USB link.

As a practical example, I want to unplug my USB mouse from my PC and plug this box inline, i.e. the mouse goes into the box and a cable from the box into the PC. Now the box must be able to insert a latency in one direction, say up to 100ms.

The practical effect is to show how a small latency affect HMI (human machine interfaces).

Makes sense?

Okay, I understand.

I suppose this should be possible with some form of *nix, but not sure how you will make it portable on an inline device.

Found this on some wiki: /sys/bus/usb-serial/devices/ttyUSB0/latency_timer

Even if possible on Raspberry, you would still need to carry around a monitor of sorts I suppose to show the effects which I guess defeats the purpose unless you get one of them bolt-on LCD screens.

 

[ponder]

/Hope this is in the right sub-forum

Looking for a "black box" solution that will introduce a configurable latency between an USB host and device. Something that's "plug-and-play". I'm doing it today with a PC and a fair amount of software but really needs something that's idiot-proof. (Something like an RPI with relevant software on it. )

I thought it'd be readily available but can't find something like it, suspect not so easy at a low level to introduce latency?

Any ideas, or anyone that could develop something like this?

Fire a support mail off to FTDI, they might have some ideas/products. I know you can specify latency 1-255ms on some of their usb-serial controllers.

I would also pick some brains over on the badcaps forum.

 

[jannievanzyl]

Fire a support mail off to FTDI, they might have some ideas/products. I know you can specify latency 1-255ms on some of their usb-serial controllers.

I would also pick some brains over on the badcaps forum.

Thanks, the FTDI link looks promising. I registered to ask on their forum as well. But, good lord, you need to win a quiz show just to register. Check this list of challenge questions just to join their forum......