.. Perun PowerDesk Documentation
   file: hwlink_error.rst
   Copyright (c) 2016
   Perun Technologies

Setting and Resetting Device Errors
===================================

The **PowerDesk** software communicates with ``LARA-100`` devices in two different ways. Each device is equipped with a ``DSP`` processor, to which a serial communication channel is established. A different, simpler and direct communication channel exists between the software and the underlying hardware using designated ``GPIO`` lines.

As soon as a connection is established towards a ``Lara-100`` device, **PowerDesk** software starts polling error ``GPIO`` lines in order to detect any hardware-related errors. These errors are of high priority, and their status is always visible, both in the **Diagnostics Pane** and in the **Project Explorer**, next to the name of the associated device.

It is possible to signal a hardware error directly from **Perun PowerDesk** by invoking the **General Stop** command, which can be located either on the **Main Ribbon** or from the device drop-down menu. This command serves as a *software emergency stop*, or *software panic button* and it forces the device to stops its operation in the safest way possible.

Any device related error signals can be reset by invoking the **General Enable** command, which is opposite to the **General Stop** in the sense that it cancels it. After calling the general enable, the device should ''recover'' from any previous invocation of **General Stop**.