GCS: Change param default SRx_PARAMS to 50

[magicrub]

GCS: Change param default SRx_PARAMS to 50. If it's too fast it will self throttle down via buffer-size detection so no reason to artificially limit ourselves by default. Of note, some vehicles had this value set to 0 which would be treated as 10 later on in GCS_MAVLINK::set_ap_message_interval()

[Hwurzburg]

I am concerned that some rc systems will have issues with their telem link if they try to read params now...you assume eveything attached to MAVlink has variable buffers....I know of at least one LRS system (Dragonlink) that is very sensitive to stream rates

[IamPete1]

I don't think this does anything for params over FTP, so I'm not really sure what the benifit is?

[WickedShell]

I don't think this does anything for params over FTP, so I'm not really sure what the benifit is?

For those of us who are not using the FTP yet, it's very relevant. I do think 50 is probably too fast, but the bandwidth reservation logic currently means that you can almost always go to 20 and still use less bandwidth then the default. (At 57600 baud).

Making this a thing that HWDEF could override would be really nice though on initial connection.

[muramura]

Expects to send at the specified period.
If the cycle varies, it will be difficult to determine the status of the aircraft.
I use a radio, carrier network and know that bandwidth is not stable.
I am hoping that this instability will cause the transmission cycle to change NG.

You can set the transmission cycle in the LUA script.
I think you can use this as a reference to change the stream rate.

https://github.com/ArduPilot/ardupilot/blob/master/libraries/AP_Scripting/examples/message_interval.lua

[peterbarker]

A GCS could do this by sending in a SET_MESSAGE_INTERVAL as desired.

Or you could create a ROMFS file to set the interval on your vehicle (https://ardupilot.org/dev/docs/mavlink-requesting-data.html#specifying-message-rates-in-a-file).

Both of those options are less likely to completely stuff people on 433MHz no-flow-control radios :-)

[rmackay9]

Like others I'm concerned about this change. I think we need to test that there is no effect for unused serial ports on Copter which current have all the serial rates set to zero by default.

[magicrub]

DevCall result: best to solve this problem in GCS