# EDrive - Communication

There are different communication protocols which transfer telegrams between devices.
The [`ComBase`](edrive.com_base.ComBase) class aims to bundle common parts of the protocol classes.

## ComBase
The [`ComBase`](edrive.com_base.ComBase) class defines interface functions used to handle I/O data and for capable device also PNU accesses.

__`start_io`__: Starts the I/O data operation
__`stop_io`__: Stops the I/O data operation
__`send_io`__: Writes provided `bytes` data to the process data outputs
__`recv_io`__: Reads from process data inputs and returns `bytes` data

For cases where PNU access is available there are also methods

__`read_pnu`__: Reads a PNU of provided index and subindex and interprets with provided datatype
__`write_pnu`__: Writes a provided PNU value to provided index and subindex as provided datatype

## ComEthernetip
Instantiating a [`ComEthernetip`](edrive.com_ethernetip.ComEthernetip) requires an IP address.
Optionally the cycle time can be provided (default is 10 ms).
Be aware that most likely your OS will be a limiting factor here.

```python
edrive = ComEthernetip('192.168.0.1', cycle_time=50)
```

## ComModbus
Instantiating a [`ComModbus`](edrive.com_modbus.ComModbus) requires an IP address.
Optionally the modbus timeout which should be configured on the endpoint can be provided (default is 1000 ms).

```python
edrive = ComModbus('192.168.0.1', timeout_ms=500)
```

# EDrive - MotionHandler
The [`MotionHandler`](edrive.motion_handler.MotionHandler) class can be used to start different motion tasks.
Under the hood it uses PROFIDRIVE telegram 111.
The intention of the class is to provide an abstraction from telegram 111 to the user, thus providing a simpler interface.

The motion class is instantiated by providing a edrive communication instance that is used to transfer the telegram (e.g. [`ComEthernetip`](edrive.com_ethernetip.ComEthernetip) or [`ComModbus`](edrive.com_modbus.ComModbus)).

```python
with MotionHandler(edrive) as mot:
```

The instance is then able of handling basic setup sequences.

```python
    mot.acknowledge_faults()
    mot.enable_powerstage()
```

And start motion tasks:

```python
    mot.position_task(position=1000, velocity=5000)
```