RoboSavvy Forum

AX12 servo replying to PING with broadcast id

2007-02-28T20:47:39+01:00

Thanks limor, I should have started another thread myself

I figured as much, and I've already updated my code to handle this case, so a ping will always respond, regardless of the state of the status return level, and regardless of whether the servo id matches or is the broadcast ID.

- Jon

Statistics: Posted by JonHylands — Wed Feb 28, 2007 8:47 pm

AX12 servo replying to PING with broadcast id

2007-02-28T20:38:31+01:00

(Jon, Sorry, I put this question into a thread on its own because the "Bioloid I/O board" thread merits some some serious focus if we are to succeed in our effort to mass produce a board)

And to answer your question, IMHO the reason for adding this feature is in a situation where you dont know the servo ID or you dont know if the servo is responding at all. You just place it by itself connected to the CM5 and send a ping with a broadcast id.
obviously doesnt make any sense in a situation where there's more than one servo on the bus.

Statistics: Posted by limor — Wed Feb 28, 2007 8:38 pm

AX12 servo replying to PING with broadcast id

2007-02-28T17:44:27+01:00

Here's a question for everyone who's playing with this stuff:

On page 22 of the AX-12 manual, it says this with respect to the PING command:

"Regardless of whether the Broadcasting ID is used or the Status Return Level (Address 16) is 0, a Status Packet is always returned by the PING instruction."

I can understand ignoring the status return level value, but broadcast???? If you had more than one device on the bus, and you sent a broadcast PING, multiple devices would be trying to respond at the same time (more or less), and the responses would be completely garbled.

However, if this is one of those "buyer beware" things, I can understand why it would work that way - if you connect just one device to the bus, you can send it a PING with the broadcast id and find out its ID.

Any thoughts on this?

- Jon

Statistics: Posted by JonHylands — Wed Feb 28, 2007 5:44 pm