SMSD.py

wheel (GHA via nightly.link)

Disclaimers

• the author of this library is not affiliated with Smart Motor Devices OÜ or НПФ Электропривод;

A library implementing protocols for Smart Motor Devices SMSD controlling drivers for stepper motors.

• SMSD-4.2LAN and SMSD-8.0LAN - implemented a protocol and a server under .lan submodule.
• SMSD-1.5K, SMSD-3.0, SMC-3 - implemented a client and classes for commands under .text submodule. Also implemented parsing of the file formats where programs are stored.

SMSD-*LAN

Server

0. Import the class and instantiate it

from SMSD.lan.protocol import Server
s = Server()

1. Create the servr using one of the following ways. 1.a. You can create a server listening on a serial port.

await s.startUARTServer("/dev/ttyACM0")

The serial port on Linux can be a pty - a virtual one, but it must be created by some other app, like socat or PyVirtualSerialPorts. But see the cavheats!

Cavheats:

• Wine COM port passthrough: symlinking to ~/.wine/dosdevices/com<number> simply doesn't work at all.
• VirtualBox COM port passthrough: a. when a VM is loaded, the virtual device must exist. You may need to restart the server while keeping the VM running. It is possible through use of the virtual serial ports tools mentioned. b. VirtualBox has the following modes of COM ports passthrough: * Host Device - results in an error when connected to a pty. OK when connected to a real device. * Host Pipe * pty - error * pipe - the communication is unidirectional. * Raw File - the communication is unidirectional. * TCP - Works! Can be set up as socat TCP-LISTEN:14379 PTY,link=./host,rawer. Bonus - wireshark can be used to listen to the communications.

ToDo: Find a way to create a non-pty virtual serial port on Linux.

1.b. You can create a TCP server. Address of listening is determined by s.networkConfig.ip, by default it is localhost.

await s.startTCPServer()

1.c You can create a TCP server listening for UART-escaped and framed messages. It will allow you to connect VirtualBox to the tool directly without socat. The IP is still determined by s.networkConfig.ip, but the port is determined by the argument passed to the func.

await s.startUARTTCPServer(port=port)

SMSD-1.5K, SMSD-3.0, SMC-3

In my case commands for using in-memory operational buffer and Direct Control mode have never worked. Neither with vendor-supplied software, nor with my one.

Don't use, unfinished and API is very unstable

P.S. I'm a very newbie to AsyncIO, so it is very probably that I use it incorrectly.

File formats used

The original SMC_Program software stores the user-created programs within pairs of files <name>.smc and <name>._smc. All the files are plain text files, where the data is stored in lines using \r\n separators and cp1251 encoding. The files are scrambled by applying rotation (byte[i] + 0x7E) & 0xFF, to descramble you need (byte[i] - 0x7E) & 0xFF. Both files are required in order to allow SMC_Program to load the program, while technically only one should be enough.

• <name>.smc contains a sequence of commands
• <name>._smc contains human-readable description of what a command does.