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UniversalRobots / Universal_Robots_ROS_Driver

Universal Robots ROS driver supporting CB3 and e-Series
Apache License 2.0
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Probe for sending script code on eSeries #13

Open fmauch opened 4 years ago

fmauch commented 4 years ago

When an e-Series robot runs in local mode, script code sent through the primary interface is ignored. However, the user doesn't get notified of this. Unfortunately, we cannot read whether the robot is currently in remote_control_mode or in local_mode.

The idea is to write a small probe routine that tries to send a string through a socket via script code and see whether we receive this string on the remote side.

fmauch commented 4 years ago

One important question is when to actually probe this. As this can be changed at any arbitrary moment while the driver is running, only probing at driver startup will not be sufficient.

Performing the check every time we want to send script code also seems wrong as this produces a quite significant delay each time a user wants to send script code.

A third option would be to perform this check cyclically. While I also don't like this method very much it seems to be the best solution currently coming to my mind.

gavanderhoorn commented 4 years ago

It would be perfect if local/remote mode would be something that can be retrieved either over RTDE or in any other way from the controller.

Then we could keep track of it locally in ur_robot_driver and act accordingly.

No need to poll or check.

Perhaps something to discuss with UR.

fmauch commented 4 years ago

Perhaps something to discuss with UR.

Forgot to mention: Already did that.

Unfortunately, there seems to be no interface (neither of URScript, primary interface, RTDE, dashbaord) to provide that information.

gavanderhoorn commented 4 years ago

Yes, right now there is no way.

It could be added.

That would make sense anyway: it's a rather basic thing to be able to export local/remote configuration from a robot controller. For instance to a PLC, to make sure the system is in a consistent state before starting a cell.

For PLC integration this is often done using IO (over a fieldbus). If that was available, those IOs could be included in the RTDE recipe perhaps. That would make it generically usable, not just for ur_robot_driver.

fmauch commented 4 years ago

Update: Since software version 5.6 there is an interface inside the dashboard server that provides this information (see also #76). However, this would still require some kind of active polling as discussed above.

gavanderhoorn commented 4 years ago

Hm. I thought I'd understood from Anders that this information was actually exported over RTDE (as well)?

Would be really unfortunate if that is not the case.