The REAL potential maximum baud rate of the BS2px?

Bill Chennault

All--

The vendor of the servo in which I am interested--the AX-12 that I have burdened you with time and again--has it talking to a BS2 at 9600 baud. (Well, I bugged him a bit, too! [noparse]:)[/noparse] If anyone wants a link to exactly how he did it, I will be glad to supply it. (He resells Parallax stuff, so I feel comfortable doing so.)

He is going to set the EEPROMs of the AX-12s I've ordered to whatever I want. Well, I wanted 19.2kbps because that is what the documentation says. IF that is correct, THEN does it apply to all i/o pins or just "PIN 16?"

If I use the maximum baud rate to communicate with my servos, are there any other caveats of which I should be aware? For example, let's say the last networked servo is 6 feet (as the wiring snakes) from either the BS2px24 or the next to last servo, whichever is worst case in this RS-485 scenario. Can I reliably communicate that distance at the maximum baud rate of the BS2px24, whatever it is?

Thank you very much.

--Bill

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allanlane5

Each time you issue a SEROUT command, you specify both the pin and the baud rate modifier. So yes, that applies to all I/O pins. "Pin 16" is a pseudo-pin, indicating to the BS2 firmware that you meant to use the "programming port" back to the PC.

The BS2 can put out like 25 mA per pin -- which I believe is close to the RS-485 specification. Worst case, you might want to put an RS485 transciever chip (like the chip they use in the AX-12) on the I/O pin you want to use to talk to the AX-12's. I believe that's good out to 4000 feet, and 32 'slave' devices.

Edit:· "Pseudo-pin" meaning there isn't really a physical pin 16, it's an indicator value to the BS2 firmware.

Bill Chennault

allanlane5--

Thanks to guys like you I actually knew that PIN 16 was a "pseudo pin". That is why I put quotes around it.

Merry Christmas!

--Bill

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You are what you write.