Revision history [back]

50Hz is not much. There is no problem with being subscribed all the time as long as the messages you send around are not too big.

I wouldn't use a ROS parameter for enabling/disabling recording because you needed to poll if the parameter is set all the time. This required doing XMLRPC calls to the master all the time which can be slow. Instead, I would use a ROS service.

You shouldn't require to deal with any timings or whatever in the subscriber. Just subscribe to a topic and write to your file whenever your callback is executed. Then the rate is controlled by the publisher. If you need a specific rate, use a throttle node (see topic_tools) as mentioned in your previous question.