A question about baud rates...
fogled@mizzou
Posts: 549
When I started with AMX stuff, almost everything I ran into was set to 9600 baud. But after my experiences with BiAmps and Polycoms, I'm thinking that I want to crank up baud rates as high as I can.
How do others approach baud rate settings?
How do others approach baud rate settings?
0
Comments
SEND_COMMAND DATA.DEVICE,'SET BAUD 9600,N,8,1 485 DISABLE'
You just adjust accordingly to device controled speed, parity, length and stop bit and everything is same in program
Hope it helps
Longer serial cables force lower baud rates, of course. I've left all my projectors at 9600 baud since they are usually a fair distance from the controller. Projectors just don't get a barrage of commands that could be dropped, either. But for devices in the same rack as the controller, cable length isn't an issue, and sometimes I have to send several commands in a row to the device. So I've been upping the baud to 115200 (or at least 57600) on these devices, and it seems like it makes the whole system just a bit "snappier".
Does anyone know whether slower baud rates actually slow down the controller? It seems like the faster I can get commands in and out of the controller, the more time the controller has to chew away on the program and be more "responsive". Then again, maybe each serial port is buffered from the CPU itself, and the actual data sending is handled by a separate serial controller. Any comments on that?
Jeremy
I tend to leave all serial devices controlled at their factory or default baud settings. I find that it's a little more fool proof. If the device somehow gets zapped or someone comes along and resets it, it comes up in factory settings. If you work with the factory settings, you tend not to get into trouble in that regard.
I typically don't find most device's serial communication to be so slow that it's unusable. Even home security systems which are painfully slow. (1200 baud) seem to do alright for most applications.
I can't see any reason to change the factory setting. I can think of reasons not to - like confusing the next guy to work on the system, or making it impossible to replace a faulty unit without looking at the code.
That said, if there is a lot of traffic, a slow baud rate just won't cut it. A media server, for example, like an Escient Fireball, would really populate a panel slowly at 9600. That you would want to bump up.
Most devices, I consider 57600 to be the practical upper limit. 115200 seems to generate errors, especially with longer wire runs.
- Chip
OK, I think I get the gist:
1. Leave baud rates at factory defaults, unless you have a REALLY good reason not to.
2. If you do change it, your documentation had better be good. Really good.
Simple enough?
Thanks for the input everyone!
NX-2200 default baud rate is 9600?
Read the docs... really, an NX has no "default baud rate"... You need to specify the rate you want to use to talk to external devices. Which do have default speeds per their manufacturers. Which are stated in their documentation.
The only "default baud rate" in an NX/NI might be in the terminal support, 38400 per the view in NetLinx Studio. But that's not i/o...
Thank's for replay @John Nagy
Sorry my ignorance. I'm noob on AMX,
I want to set the AMX baud rate on a rs-232 port on an NX-2200. Would the correct code be this?
DEFINE_DEVICE
dvIPServer1 = 0:1:0 (AMX)
DEFINE_EVENT
data_event[dvIPServer1]
{
online:
{
send_command 5001:1:0,'SET BAUD 9600,N,8,1'
send_command 5001:2:0,'SET BAUD 9600,N,8,1'
}
}
Please don't double post. Most of us browse 'Recent discussions' , not separate categories.
One of your post will likely stay unanswered or the answers will be spread among your two posts. That won't be helpful.
Just as an advice
I answered your other post, BTW.
EDIT: Mhh, now saw you posted the same thing 3 times. So it's in one of the other threads. Again, please don't do that ...
Sorry @richardherman. And thank you! You saved my life!