diff --git a/Tools/px4params/xmlout.py b/Tools/px4params/xmlout.py
index f10d5f4fd2..21ed9aa923 100644
--- a/Tools/px4params/xmlout.py
+++ b/Tools/px4params/xmlout.py
@@ -25,7 +25,7 @@ class XMLOutput():
         xml_version = ET.SubElement(xml_parameters, "parameter_version_major")
         xml_version.text = "1"
         xml_version = ET.SubElement(xml_parameters, "parameter_version_minor")
-        xml_version.text = "12"
+        xml_version.text = "13"
         importtree = ET.parse(inject_xml_file_name)
         injectgroups = importtree.getroot().findall("group")
         for igroup in injectgroups:
diff --git a/src/drivers/px4fmu/px4fmu_params.c b/src/drivers/px4fmu/px4fmu_params.c
index 19afcd77a3..9d0b341a7a 100644
--- a/src/drivers/px4fmu/px4fmu_params.c
+++ b/src/drivers/px4fmu/px4fmu_params.c
@@ -111,7 +111,7 @@ PARAM_DEFINE_INT32(PWM_AUX_REV6, 0);
 /**
  * Trim value for FMU PWM output channel 1
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
@@ -123,7 +123,7 @@ PARAM_DEFINE_FLOAT(PWM_AUX_TRIM1, 0);
 /**
  * Trim value for FMU PWM output channel 2
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
@@ -135,7 +135,7 @@ PARAM_DEFINE_FLOAT(PWM_AUX_TRIM2, 0);
 /**
  * Trim value for FMU PWM output channel 3
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
@@ -147,7 +147,7 @@ PARAM_DEFINE_FLOAT(PWM_AUX_TRIM3, 0);
 /**
  * Trim value for FMU PWM output channel 4
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
@@ -159,7 +159,7 @@ PARAM_DEFINE_FLOAT(PWM_AUX_TRIM4, 0);
 /**
  * Trim value for FMU PWM output channel 5
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
@@ -171,7 +171,7 @@ PARAM_DEFINE_FLOAT(PWM_AUX_TRIM5, 0);
 /**
  * Trim value for FMU PWM output channel 6
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
  * @min -0.2
  * @max 0.2
diff --git a/src/drivers/px4io/px4io.cpp b/src/drivers/px4io/px4io.cpp
index c1cba71300..93bead77e8 100644
--- a/src/drivers/px4io/px4io.cpp
+++ b/src/drivers/px4io/px4io.cpp
@@ -1207,12 +1207,12 @@ PX4IO::task_main()
 				// update trim values
 				struct pwm_output_values pwm_values;
 
-				memset(&pwm_values, 0, sizeof(pwm_values));
-				ret = io_reg_get(PX4IO_PAGE_CONTROL_TRIM_PWM, 0, (uint16_t *)pwm_values.values, _max_actuators);
+//				memset(&pwm_values, 0, sizeof(pwm_values));
+//				ret = io_reg_get(PX4IO_PAGE_CONTROL_TRIM_PWM, 0, (uint16_t *)pwm_values.values, _max_actuators);
 
 				for (unsigned i = 0; i < _max_actuators; i++) {
 					char pname[16];
-					int32_t ival;
+					float pval;
 
 					/* fetch the trim values from parameters */
 					sprintf(pname, "PWM_MAIN_TRIM%u", i + 1);
@@ -1220,8 +1220,8 @@ PX4IO::task_main()
 
 					if (param_h != PARAM_INVALID) {
 
-						param_get(param_h, &ival);
-						pwm_values.values[i] = ival;
+						param_get(param_h, &pval);
+						pwm_values.values[i] = (int16_t)(10000 * pval);
 					}
 				}
 
diff --git a/src/drivers/px4io/px4io_params.c b/src/drivers/px4io/px4io_params.c
index 85f16c0a2a..0f2a6fbb1c 100644
--- a/src/drivers/px4io/px4io_params.c
+++ b/src/drivers/px4io/px4io_params.c
@@ -133,90 +133,98 @@ PARAM_DEFINE_INT32(PWM_MAIN_REV8, 0);
 /**
  * Trim value for main output channel 1
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM1, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM1, 0);
 
 /**
  * Trim value for main output channel 2
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM2, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM2, 0);
 
 /**
  * Trim value for main output channel 3
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM3, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM3, 0);
 
 /**
  * Trim value for main output channel 4
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM4, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM4, 0);
 
 /**
  * Trim value for main output channel 5
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM5, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM5, 0);
 
 /**
  * Trim value for main output channel 6
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM6, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM6, 0);
 
 /**
  * Trim value for main output channel 7
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM7, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM7, 0);
 
 /**
  * Trim value for main output channel 8
  *
- * Set to neutral period in usec
+ * Set to normalized offset
  *
- * @min 1400
- * @max 1600
+ * @min -0.2
+ * @max 0.2
+ * @decimal 2
  * @group PWM Outputs
  */
-PARAM_DEFINE_INT32(PWM_MAIN_TRIM8, 1500);
+PARAM_DEFINE_FLOAT(PWM_MAIN_TRIM8, 0);
 
 /**
  * S.BUS out
diff --git a/src/modules/px4iofirmware/registers.c b/src/modules/px4iofirmware/registers.c
index 22029b91f8..f535bfa7e8 100644
--- a/src/modules/px4iofirmware/registers.c
+++ b/src/modules/px4iofirmware/registers.c
@@ -399,19 +399,19 @@ registers_set(uint8_t page, uint8_t offset, const uint16_t *values, unsigned num
 		/* copy channel data */
 		while ((offset < PX4IO_SERVO_COUNT) && (num_values > 0)) {
 
-			if (*values == 0) {
-				/* allow 0 - turns the trim option off */
-				r_page_servo_control_trim[offset] = 0;
-
-			} else if (*values > PWM_HIGHEST_MAX) {
-				r_page_servo_control_trim[offset] = PWM_HIGHEST_MAX;
-
-			} else if (*values < PWM_LOWEST_MAX) {
-				r_page_servo_control_trim[offset] = PWM_LOWEST_MAX;
-
-			} else {
-				r_page_servo_control_trim[offset] = *values;
-			}
+//			if (*values == 0) {
+//				/* allow 0 - turns the trim option off */
+//				r_page_servo_control_trim[offset] = 0;
+//
+//			} else if (*values > PWM_HIGHEST_MAX) {
+//				r_page_servo_control_trim[offset] = PWM_HIGHEST_MAX;
+//
+//			} else if (*values < PWM_LOWEST_MAX) {
+//				r_page_servo_control_trim[offset] = PWM_LOWEST_MAX;
+//
+//			} else {
+			r_page_servo_control_trim[offset] = *values;
+//			}
 
 			offset++;
 			num_values--;