How to use the table prefix to code a project in phalcon?

One way to acomplish this is to include the table prefix within your config object. For each model that you define, you will also need the set the source so that the table prefix is applied.

config.php

return new \Phalcon\Config(array(
    'db' => array(
        'tblPrefix' => 'xyz_'
    )
));

Robot Model

class Robots extends \Phalcon\Mvc\Collection
{
    public function getSource()
    {
        $source = $this->getDi()->getConfig()->db->tblPrefix . 'robots';
        return $source;
    }
}

services.php

$config = include APPLICATION_PATH . '/config/config.php';
$di->set('config', $config);