07-31-2017, 11:12 PM
(07-31-2017, 09:51 PM)Briney Eye Wrote: From homeshopmachinist:
The transmission is with 19.2KBaud. (usual mode: 8 Data bits 1 Stop bit, no parity)
Although it's a RS485 transceiver it has a termination resistor of 470Ohm and not the usual 120Ohm. Maybe the AT715 has not enough power to drive a 120Ohm line.
Each signal line is PU/PD accordingly to it's level with a 2k resistor.
The AT715 sends its position every 50ms (20 times/second), so it is surely not usable for realtime controlling.
It always sends 6 Bytes in a row
The first byte is always zero
Then there are 4 Bytes for the absolute position (resolution 0.5um) with LSB first. Negative values are in twos complement.
The last byte is a checksum (just all other bytes added).
Yeah, that will not work with any of the controllers. This is their weird protocol from the 80's...