- RS422 differential Sender / Receiver -
Circuit and PCB's
There is not much to say about the circuit. It is based on the RS422 sender and receiver AM26LS31 und AM26LS32 that is manufactured by Texas Instruments. The circuit uses 3 of the four channels of the devices. It is therefore suitable for motor encoders with optional index signals and also for hall-sensors.
Please note that the pinout of the connectors is compatible for HEDS encoders manufactured by Avago and also for their connectors on the UPCS boards. To connec hall-sensors to them, some signals have to be swapped within the connecting cable.
The board size is 26mm x 32mm (sender) and 23mm x 32mm (receiver). Because the boards are so small they are mounted via the DB-9 connector onto a case.
There is nothing to watch out when soldering the boards.
Because of the low count of components on the boards, I do not provide a list of parts within the project files.
The connection Cable
To connect the two boards, use a common used 9 pin serial cable. All pins must be connected straight thru. The cabe needs a male connector on one side and a female connector on the other side.