8051 multi-drop serial communications

ksltd

Hi,

I can't seem to find any support for the 8031/8051 9-bit multi-drop serial communication protocol. Has anyone got such an object laying about?

Thanks!

jmg

Any SW uart is going to have the bit-length as a constant, loaded into a BitCounter, so will be easy to adjust to 9 bits.
Find an object that has the right specs for Baud rate and message size, and it should be easy to modify to length setting to 9bits, and add the handling of that 9th bit, and talk to 8051 slaves.

Don M

ksltd wrote: »

Hi,

I can't seem to find any support for the 8031/8051 9-bit multi-drop serial communication protocol. Has anyone got such an object laying about?

Thanks!

Vending machine / VMC / payment systems MDB ?

VIRAND

As I recall the ninth bit wakes up the 8051 to expect its net address, and it goes back to sleep if it doesn't find it and ignores the rest of the packet which is intended for some other 8051. I think you just have to duplicate a serial object with one change for sending net addresses, which is, the first stop bit sent should be zero for all data or one for a net address.