diff --git a/lib/Interpreter/Interpreter.php b/lib/Interpreter/Interpreter.php
index 1b9bdd5..d53ac5b 100644
--- a/lib/Interpreter/Interpreter.php
+++ b/lib/Interpreter/Interpreter.php
@@ -159,11 +159,11 @@ abstract class Interpreter {
 		$sql = '';
 
 		if (isset($from)) {
-			$sql .= '  AND timestamp >= ' . $from;
+			$sql .= ' AND timestamp >= ' . $from;
 		}
 
 		if (isset($to)) {
-			$sql .= '  AND timestamp <= ' . $to;
+			$sql .= ' AND timestamp <= ' . $to;
 		}
 
 		return $sql;
diff --git a/lib/Interpreter/MeterInterpreter.php b/lib/Interpreter/MeterInterpreter.php
index c8a5d10..f9b8913 100644
--- a/lib/Interpreter/MeterInterpreter.php
+++ b/lib/Interpreter/MeterInterpreter.php
@@ -38,12 +38,12 @@ class MeterInterpreter extends Interpreter {
 	/**
 	 * Calculates the consumption for interval speciefied by $from and $to
 	 *
-	 * @todo reimplement according to new env
+	 * @todo improfve workaround
 	 */
 	public function getConsumption() {
-		$sql = 'SELECT COUNT(*) FROM `data` WHERE `channel_id` = ' . $this->channel->getId() . parent::buildDateTimeFilterSQL($this->from, $this->to);
+		$sql = 'SELECT COUNT(*) FROM `data` WHERE `channel_id` = ?' . parent::buildDateTimeFilterSQL($this->from, $this->to);
 
-		return $this->conn->fetchColumn($sql, array($this->channel->getId()), 0)/$this->channel->getProperty('resolution');     // return KWh
+		return $this->conn->fetchColumn($sql, array($this->channel->getId()), 0) / $this->channel->getProperty('resolution');     // return KWh
 	}
 
 	/**
@@ -92,13 +92,13 @@ class MeterInterpreter extends Interpreter {
 	 * @todo untested
 	 * @return array with timestamp, values, and pulse count
 	 */
-	public function getValues($tuples = NULL, $groupBy = NULL) {
+	public function getValues($tuples, $groupBy, $callback) {
 		$pulses = parent::getData($tuples, $groupBy);
 
 		$values = array();
 		foreach ($pulses as $pulse) {
 			if (isset($last)) {
-				$values[] = $this->raw2differential($last, $pulse);
+				$values[] = $callback($this->raw2differential($last, $pulse));
 				$last = $pulse;
 			}
 			else {
diff --git a/lib/Interpreter/SensorInterpreter.php b/lib/Interpreter/SensorInterpreter.php
index 00fb815..b6f5dfc 100644
--- a/lib/Interpreter/SensorInterpreter.php
+++ b/lib/Interpreter/SensorInterpreter.php
@@ -37,16 +37,16 @@ class SensorInterpreter extends Interpreter {
 	 * @todo untested
 	 * @param string|integer $groupBy
 	 */
-	public function getValues($tuples = NULL, $groupBy = NULL) {
+	public function getValues($tuples, $groupBy, $callback) {
 		$data = parent::getData($tuples, $groupBy);
 
 		$values = array();
 		foreach ($data as $reading) {
-			$values[] = array(
+			$values[] = $callback(array(
 				(float) $reading[0],
 				(float) $reading[1] / $reading[2],
 				(int) $reading[2]
-			);
+			));
 		}
 
 		return $values;
@@ -80,14 +80,6 @@ class SensorInterpreter extends Interpreter {
 	public function getAverage() {
 		return (float) $this->conn->fetchColumn('SELECT AVG(value) FROM data WHERE channel_id = ?' . parent::buildDateTimeFilterSQL($this->from, $this->to), array($this->channel->getId()), 0);
 	}
-
-	/**
-	 * @todo possible and/or required?
-	 * @return float
-	 */
-	public function getConsumption() {
-
-	}
 }
 
 ?>
diff --git a/lib/View/CSV.php b/lib/View/CSV.php
index b08bcca..80ea0cc 100644
--- a/lib/View/CSV.php
+++ b/lib/View/CSV.php
@@ -35,8 +35,8 @@ use Volkszaehler\Interpreter;
  * @todo rework
  */
 class CSV extends View {
-	protected $delimiter = ';';
-	protected $enclosure = '"';
+	const DELIMITER = ';';
+	const ENCLOSURE = '"';
 
 	protected $csv = array();
 
@@ -115,14 +115,19 @@ class CSV extends View {
 	 * @param Interpreter\InterpreterInterface $interpreter
 	 */
 	protected function addData(Interpreter\Interpreter $interpreter) {
-		$tuples = $interpreter->getValues($this->request->getParameter('tuples'), $this->request->getParameter('group'));
-		
 		//$this->response->setHeader('Content-Disposition', 'attachment; filename="' . strtolower($interpreter->getEntity()->getProperty('title')) . '.csv"'); // TODO add time?
-	
-		foreach ($tuples as $row) {
-			$array = array_map(array($this, 'escape'), $row);
-			echo implode($this->delimiter, $row) . PHP_EOL;
-		}
+		
+		$tuples = $interpreter->getValues(
+			$this->request->getParameter('tuples'),
+			$this->request->getParameter('group'), 
+			function($tuple) {
+				echo implode(CSV::DELIMITER, array(
+					$tuple[0],
+					View::formatNumber($tuple[1]),
+					$tuple[2]
+				)) . PHP_EOL; 
+			}
+		);
 	}
 
 	/**
@@ -138,7 +143,7 @@ class CSV extends View {
 	 */
 	protected function escape($value) {
 		if (is_string($value)) {
-			return $this->enclosure . $value . $this->enclosure;
+			return self::ENCLOSURE . $value . self::ENCLOSURE;
 		}
 		elseif (is_numeric($value)) {
 			return $value;
diff --git a/lib/View/JSON.php b/lib/View/JSON.php
index 5ccf14c..848f3c3 100644
--- a/lib/View/JSON.php
+++ b/lib/View/JSON.php
@@ -171,7 +171,7 @@ class JSON extends View {
 		if (count($queries) > 0) {
 			$jsonDebug['database'] = array(
 				'driver' => Util\Configuration::read('db.driver'),
-				'queries' => $queries
+				'queries' => array_values($queries)
 			);
 		}
 
@@ -208,19 +208,31 @@ class JSON extends View {
 	/**
 	 * Add data to output queue
 	 *
-	 * @param Interpreter\InterpreterInterface $interpreter
+	 * @param $interpreter
 	 */
-	protected function addData(Interpreter\Interpreter $interpreter) {
+	protected function addData($interpreter) {
 		$this->json['data']['uuid'] = $interpreter->getEntity()->getUuid();
 
-		$data = $interpreter->getValues($this->request->getParameter('tuples'), $this->request->getParameter('group'));
+		$data = $interpreter->getValues(
+			$this->request->getParameter('tuples'),
+			$this->request->getParameter('group'), 
+			function($tuple) {
+				return array(
+					$tuple[0],
+					View::formatNumber($tuple[1]),
+					$tuple[2]
+				);
+			}
+		);
 		$min = $interpreter->getMin();
 		$max = $interpreter->getMax();
 		$average = $interpreter->getAverage();
+		$consumption = $interpreter->getConsumption();
 		
-		if (isset($min)) $this->json['data']['min'] = $min;
-		if (isset($max)) $this->json['data']['max'] = $max;
-		if (isset($average)) $this->json['data']['average'] = $average;
+		$this->json['data']['min'] = $min;
+		$this->json['data']['max'] = $max;
+		$this->json['data']['average'] = View::formatNumber($average);
+		$this->json['data']['consumption'] = View::formatNumber($consumption);
 		if (count($data) > 0) $this->json['data']['tuples'] = $data;
 	}
 
diff --git a/lib/View/View.php b/lib/View/View.php
index 5003a03..9bbb599 100644
--- a/lib/View/View.php
+++ b/lib/View/View.php
@@ -137,6 +137,16 @@ abstract class View {
 				throw new Exception('Unknown caching mode: ' . $mode);
 		}
 	}
+	
+	/**
+	 * Round decimal numbers to given precission
+	 *
+	 * @param $number float the number
+	 * @return (float|string) the formatted number
+	 */
+	public static function formatNumber($number) {
+		return round($number, self::PRECISSION);
+	}
 
 	public abstract function add($object);
 	protected abstract function render();
diff --git a/lib/View/XML.php b/lib/View/XML.php
index 1fb1520..70327b9 100644
--- a/lib/View/XML.php
+++ b/lib/View/XML.php
@@ -75,10 +75,10 @@ class XML extends View {
 			$this->addEntity($data);
 		}
 		elseif ($data instanceof \Exception) {
-			//$this->addException($data);
+			$this->addException($data);
 		}
 		elseif ($data instanceof Util\Debug) {
-			//$this->addDebug($data);
+			$this->addDebug($data);
 		}
 		elseif (is_array($data)) {
 			$this->xmlRoot->appendChild($this->convertArray($data));
@@ -163,11 +163,11 @@ class XML extends View {
 	protected function addDebug(Util\Debug $debug) {
 		$xmlDebug = $this->xmlDoc->createElement('debug');
 		$xmlDebug->appendChild($this->xmlDoc->createElement('time', $debug->getExecutionTime()));
-		$xmlDebug->appendChild($this->convertArray($debug->getMessages(), 'messages'));
+		$xmlDebug->appendChild($this->convertArray($debug->getMessages(), 'messages', 'message'));
 		
 		$xmlDatabase = $this->xmlDoc->createElement('database');
 		$xmlDatabase->setAttribute('driver', Util\Configuration::read('db.driver'));
-		$xmlDatabase->appendChild($this->convertArray($debug->getQueries(), 'queries'));
+		$xmlDatabase->appendChild($this->convertArray($debug->getQueries(), 'queries', 'query'));
 
 		$xmlDebug->appendChild($xmlDatabase);
 		$this->xmlRoot->appendChild($xmlDebug);
@@ -198,28 +198,30 @@ class XML extends View {
 	/**
 	 * Add data to output queue
 	 *
-	 * @param Interpreter\InterpreterInterface $interpreter
+	 * @param $interpreter
 	 */
-	protected function addData(Interpreter\InterpreterInterface $interpreter) {
-		$data = $interpreter->getValues($this->request->getParameter('tuples'), $this->request->getParameter('group'));
+	protected function addData($interpreter) {
+		$xmlDoc = $this->xmlDoc;
 		$xmlData = $this->xmlDoc->createElement('data');
 		$xmlTuples = $this->xmlDoc->createElement('tuples');
-		foreach ($data as $tuple) {
-			$xmlTuple = $this->xmlDoc->createElement('tuple');
-			$xmlTuple->setAttribute('timestamp', $tuple[0]);	// hardcoded data fields for performance optimization
-			$xmlTuple->setAttribute('value', $tuple[1]);
-			$xmlTuple->setAttribute('count', $tuple[2]);
-			$xmlTuples->appendChild($xmlTuple);
-		}
-
+		
+		$data = $interpreter->getValues(
+			$this->request->getParameter('tuples'),
+			$this->request->getParameter('group'), 
+			function($tuple) use ($xmlDoc, $xmlTuples) {
+				$xmlTuple = $xmlDoc->createElement('tuple');
+				$xmlTuple->setAttribute('timestamp', $tuple[0]);	// hardcoded data fields for performance optimization
+				$xmlTuple->setAttribute('value', View::formatNumber($tuple[1]));
+				$xmlTuple->setAttribute('count', $tuple[2]);
+				$xmlTuples->appendChild($xmlTuple);
+			}
+		);
+		
 		$xmlData->appendChild($this->xmlDoc->createElement('uuid', $interpreter->getEntity()->getUuid()));
-		$xmlData->appendChild($this->xmlDoc->createElement('count', count($data)));
-		$xmlData->appendChild($this->xmlDoc->createElement('first', (isset($data[0][0])) ? $data[0][0] : NULL));
-		$xmlData->appendChild($this->xmlDoc->createElement('last', (isset($data[count($data)-1][0])) ? $data[count($data)-1][0] : NULL));
 		$xmlData->appendChild($this->xmlDoc->createElement('min', $interpreter->getMin()));
 		$xmlData->appendChild($this->xmlDoc->createElement('max', $interpreter->getMax()));
-		$xmlData->appendChild($this->xmlDoc->createElement('average', $interpreter->getAverage()));
-		$xmlData->appendChild($this->xmlDoc->createElement('last', $interpreter->getLast()));
+		$xmlData->appendChild($this->xmlDoc->createElement('average', self::formatNumber($interpreter->getAverage())));
+		$xmlData->appendChild($this->xmlDoc->createElement('consumption', self::formatNumber($interpreter->getConsumption())));
 		$xmlData->appendChild($xmlTuples);
 	
 		$this->xmlRoot->appendChild($xmlData);
@@ -231,28 +233,25 @@ class XML extends View {
 	 * @param array the input array
 	 * @return DOMElement
 	 */
-	protected function convertArray(array $array, $identifier = 'array') {
-		$xmlArray = $this->xmlDoc->createElement($identifier);
+	protected function convertArray(array $array, $identifierPlural = 'array', $identifierSingular = 'entry') {
+		$xmlArray = $this->xmlDoc->createElement($identifierPlural);
 
 		foreach ($array as $key => $value) {
-			// determine tagname
 			if (is_numeric($key)) {
-				if (substr($identifier, -3) == 'ies') {
-					$key = substr($identifier, 0, -3) . 'y';
-				}
-				elseif (substr($identifier, -1) == 's') {
-					$key = substr($identifier, 0, -1);
-				}
-				else {
-					$key = 'index' . $key;
-				}
+				$key = $identifierSingular;
 			}
 
 			if (is_array($value)) {
 				$xmlArray->appendChild($this->convertArray($value, $key));
 			}
-			else {
-				$xmlArray->appendChild($this->xmlDoc->createElement($key, (is_scalar($value)) ? $value : 'object'));
+			elseif (is_numeric($value)) {
+				$xmlArray->appendChild($this->xmlDoc->createElement($key, self::formatNumber($value)));
+			}
+			elseif (is_scalar($value)) {
+				$xmlArray->appendChild($this->xmlDoc->createElement($key, $value));
+			}
+			else { // TODO required?
+				$xmlArray->appendChild($this->xmlDoc->createElement($key, 'object'));
 			}
 		}
 		
diff --git a/misc/tools/doctrine.php b/misc/tools/doctrine.php
index 4ef6716..bdc566f 100644
--- a/misc/tools/doctrine.php
+++ b/misc/tools/doctrine.php
@@ -26,8 +26,6 @@
 
 use Volkszaehler\Util;
 
-// TODO replace by state class
-define('VZ_VERSION', 0.2);
 define('VZ_DIR', realpath(__DIR__ . '/../..'));
 
 // class autoloading