diff --git a/modules/tracker/tests/controllers/ApiControllerTest.php b/modules/tracker/tests/controllers/ApiComponentTest.php
similarity index 53%
rename from modules/tracker/tests/controllers/ApiControllerTest.php
rename to modules/tracker/tests/controllers/ApiComponentTest.php
index 6788a6325..9fddce300 100644
--- a/modules/tracker/tests/controllers/ApiControllerTest.php
+++ b/modules/tracker/tests/controllers/ApiComponentTest.php
@@ -21,7 +21,7 @@
 require_once BASE_PATH.'/modules/api/tests/controllers/CallMethodsTestCase.php';
 
 /** API test for tracker module. */
-class Tracker_ApiControllerTest extends Api_CallMethodsTestCase
+class Tracker_ApiComponentTest extends Api_CallMethodsTestCase
 {
     public $moduleName = 'tracker';
 
@@ -50,8 +50,10 @@ public function testUploadScalarWithSubmission()
 
         $outputs = array();
         $outputs['metric_0'] = $this->_submitScalar($token, $uuid, 'metric_0', '18');
-        $outputs['metric_1'] = $this->_submitScalar($token, $uuid, 'metric_1', '19', 'meters');
-        $outputs['metric_2'] = $this->_submitScalar($token, $uuid, 'metric_2', '20', 'mm');
+        $metric1Params = array('num_param' => 19.0, 'text_param' => 'metric1 text', 'null_param' => null);
+        $outputs['metric_1'] = $this->_submitScalar($token, $uuid, 'metric_1', '19', 'meters', $metric1Params);
+        $metric2Params = array('num_param' => 20.0, 'text_param' => 'metric2 text', 'null_param' => null);
+        $outputs['metric_2'] = $this->_submitScalar($token, $uuid, 'metric_2', '20', 'mm', $metric2Params);
 
         /** @var Tracker_SubmissionModel $submissionModel */
         $submissionModel = MidasLoader::loadModel('Submission', 'tracker');
@@ -60,12 +62,67 @@ public function testUploadScalarWithSubmission()
         $submissionDao = $submissionModel->getSubmission($uuid);
         $scalarDaos = $submissionModel->getScalars($submissionDao);
 
+        // Maps the scalars for each metric.
+        $metricToScalar = array();
+
         /** @var Tracker_ScalarDao $scalarDao */
         foreach ($scalarDaos as $scalarDao) {
             $curOutput = $outputs[$scalarDao->getTrend()->getMetricName()];
+            $metricToScalar[$scalarDao->getTrend()->getMetricName()] = $scalarDao;
             $this->assertEquals($curOutput->value, $scalarDao->getValue());
             $this->assertEquals($submissionDao->getKey(), $scalarDao->getSubmissionId());
         }
+
+        // Params should be a zero element array here.
+        $this->assertTrue(!($metricToScalar['metric_0']->getParams()));
+
+        $metric_1_params = $metricToScalar['metric_1']->getParams();
+        $metric_1_paramChecks = array(
+            'num_param' => array('found' => false, 'type' => 'numeric', 'val' => 19.0),
+            'text_param' => array('found' => false, 'type' => 'text', 'val' => 'metric1 text'),
+            'null_param' => array('found' => false, 'type' => 'text', 'val' => ''),
+        );
+
+        // Test that the params are saved as the correct type and value.
+        foreach ($metric_1_params as $param) {
+            $checks = $metric_1_paramChecks[$param->getParamName()];
+            $this->assertEquals($checks['type'], $param->getParamType());
+            if ($checks['type'] === 'numeric') {
+                $this->assertEquals($checks['val'], $param->getNumericValue());
+            } else {
+                $this->assertEquals($checks['val'], $param->getTextValue());
+            }
+            $metric_1_paramChecks[$param->getParamName()]['found'] = true;
+        }
+
+        // Test that all params are tested.
+        foreach ($metric_1_paramChecks as $checks) {
+            $this->assertTrue($checks['found']);
+        }
+
+        $metric_2_params = $metricToScalar['metric_2']->getParams();
+        $metric_2_paramChecks = array(
+            'num_param' => array('found' => false, 'type' => 'numeric', 'val' => 20.0),
+            'text_param' => array('found' => false, 'type' => 'text', 'val' => 'metric2 text'),
+            'null_param' => array('found' => false, 'type' => 'text', 'val' => ''),
+        );
+
+        // Test that the params are saved as the correct type and value.
+        foreach ($metric_2_params as $param) {
+            $checks = $metric_2_paramChecks[$param->getParamName()];
+            $this->assertEquals($checks['type'], $param->getParamType());
+            if ($checks['type'] === 'numeric') {
+                $this->assertEquals($checks['val'], $param->getNumericValue());
+            } else {
+                $this->assertEquals($checks['val'], $param->getTextValue());
+            }
+            $metric_2_paramChecks[$param->getParamName()]['found'] = true;
+        }
+
+        // Test that all params are tested.
+        foreach ($metric_2_paramChecks as $checks) {
+            $this->assertTrue($checks['found']);
+        }
     }
 
     /**
@@ -76,9 +133,10 @@ public function testUploadScalarWithSubmission()
      * @param string $metric the metric name of the trend
      * @param float $value the scalar value
      * @param false|string $unit (Optional) the unit of the trend, defaults to false
+     * @param false|array $scalarParams (Optional) the params of the scalar, defaults to false
      * @return mixed response object from the API
      */
-    private function _submitScalar($token, $uuid, $metric, $value, $unit = false)
+    private function _submitScalar($token, $uuid, $metric, $value, $unit = false, $scalarParams = false)
     {
         $this->resetAll();
         $this->params['method'] = 'midas.tracker.scalar.add';
@@ -93,7 +151,9 @@ private function _submitScalar($token, $uuid, $metric, $value, $unit = false)
         if ($unit !== false) {
             $this->params['unit'] = $unit;
         }
-
+        if ($scalarParams !== false) {
+            $this->params['params'] = json_encode($scalarParams);
+        }
         $res = $this->_callJsonApi();
 
         return $res->data;
diff --git a/modules/tracker/tests/controllers/ApiScalarComponentTest.php b/modules/tracker/tests/controllers/ApiScalarComponentTest.php
new file mode 100644
index 000000000..52769f547
--- /dev/null
+++ b/modules/tracker/tests/controllers/ApiScalarComponentTest.php
@@ -0,0 +1,104 @@
+<?php
+/*=========================================================================
+ Midas Server
+ Copyright Kitware SAS, 26 rue Louis Guérin, 69100 Villeurbanne, France.
+ All rights reserved.
+ For more information visit http://www.kitware.com/.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0.txt
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+=========================================================================*/
+
+require_once BASE_PATH.'/core/tests/controllers/api/RestCallMethodsTestCase.php';
+
+/** API test for tracker module ApiscalarComponent. */
+class Tracker_ApiScalarComponentTest extends RestCallMethodsTestCase
+{
+    public $moduleName = 'tracker';
+
+    /** Setup. */
+    public function setUp()
+    {
+        $this->enabledModules = array('api', 'scheduler', $this->moduleName);
+        $this->_models = array('Assetstore', 'Community', 'Setting', 'User');
+
+        $this->setupDatabase(array('default'));
+        $this->setupDatabase(array('default'), 'tracker');
+
+        ControllerTestCase::setUp();
+    }
+
+    /**
+     * Test updating an existing scalar with a set of params, via PUT.
+     *
+     * @throws Zend_Exception
+     */
+    public function testPUT()
+    {
+        $usersFile = $this->loadData('User', 'default');
+        $userDao = $this->User->load($usersFile[0]->getKey());
+
+        // Create a scalar attached to a trend.
+
+        $trendModel = MidasLoader::loadModel('Trend', 'tracker');
+        $trend = $trendModel->load(1);
+
+        $scalarModel = MidasLoader::loadModel('Scalar', 'tracker');
+        $scalarArgs = array(
+            'trend_id' => $trend->getTrendId(),
+            'value' => 42,
+            'build_results_url' => 'http://localhost',
+        );
+        $scalar = $scalarModel->initDao('Scalar', $scalarArgs, $this->moduleName);
+        $scalarModel->save($scalar);
+
+        $token = $this->_loginAsAdministrator();
+
+        $params = array(
+            'num_param' => 90,
+            'text_param' => 'master',
+            'null_param' => '',
+        );
+        $restParams = array(
+            'trend_id' => $trend->getTrendId(),
+            'params' => json_encode($params),
+            'token' => $token,
+        );
+
+        $this->resetAll();
+        $this->params = $restParams;
+        $resp = $this->_callRestApi('PUT', '/tracker/scalar/'.$scalar->getScalarId());
+
+        // Ensure params are properly set on scalar.
+
+        $paramChecks = array(
+            'num_param' => array('found' => false, 'type' => 'numeric', 'val' => 90),
+            'text_param' => array('found' => false, 'type' => 'text', 'val' => 'master'),
+            'null_param' => array('found' => false, 'type' => 'text', 'val' => ''),
+        );
+
+        foreach ($scalar->getParams() as $param) {
+            $checks = $paramChecks[$param->getParamName()];
+            $this->assertEquals($checks['type'], $param->getParamType());
+            if ($checks['type'] === 'numeric') {
+                $this->assertEquals($checks['val'], $param->getNumericValue());
+            } else {
+                $this->assertEquals($checks['val'], $param->getTextValue());
+            }
+            $paramChecks[$param->getParamName()]['found'] = true;
+        }
+
+        foreach ($paramChecks as $checks) {
+            $this->assertTrue($checks['found']);
+        }
+    }
+}
diff --git a/modules/tracker/tests/controllers/CMakeLists.txt b/modules/tracker/tests/controllers/CMakeLists.txt
index a6bfb616b..6e4b16561 100644
--- a/modules/tracker/tests/controllers/CMakeLists.txt
+++ b/modules/tracker/tests/controllers/CMakeLists.txt
@@ -20,4 +20,5 @@
 set(module_name tracker)
 to_titlecase(${module_name} module_name_titlecase)
 
-add_midas_test(${module_name_titlecase}ApiController ApiControllerTest.php)
+add_midas_test(${module_name_titlecase}ApiComponent ApiComponentTest.php)
+add_midas_test(${module_name_titlecase}ApiScalarComponent ApiScalarComponentTest.php)