diff --git a/pytec/pytec/gui/view/param_tree.json b/pytec/pytec/gui/view/param_tree.json
index e495b84..bf490dc 100644
--- a/pytec/pytec/gui/view/param_tree.json
+++ b/pytec/pytec/gui/view/param_tree.json
@@ -46,11 +46,10 @@
                       "triggerOnShow":true,
                       "decimals":6,
                       "suffix":"mA",
-                      "param":[
-                         "pwm",
-                         "ch",
-                         "i_set"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pwm",
+                        "field":"i_set"
+                      },
                       "lock":false
                    },
                    {
@@ -63,11 +62,10 @@
                          300
                       ],
                       "format":"{value:.4f} °C",
-                      "param":[
-                         "pid",
-                         "ch",
-                         "target"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pid",
+                        "field":"target"
+                      },
                       "lock":false
                    }
                 ]
@@ -88,11 +86,10 @@
                          2000
                       ],
                       "suffix":"mA",
-                      "param":[
-                         "pwm",
-                         "ch",
-                         "max_i_pos"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pwm",
+                        "field":"max_i_pos"
+                      },
                       "lock":false
                    },
                    {
@@ -106,11 +103,10 @@
                          2000
                       ],
                       "suffix":"mA",
-                      "param":[
-                         "pwm",
-                         "ch",
-                         "max_i_neg"
-                      ],
+                      "thermostat:set_param":{
+                         "topic":"pwm",
+                         "field":"max_i_neg"
+                      },
                       "lock":false
                    },
                    {
@@ -124,11 +120,10 @@
                       ],
                       "siPrefix":true,
                       "suffix":"V",
-                      "param":[
-                         "pwm",
-                         "ch",
-                         "max_v"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pwm",
+                        "field":"max_v"
+                      },
                       "lock":false
                    }
                 ]
@@ -150,11 +145,10 @@
                    100
                 ],
                 "format":"{value:.4f} °C",
-                "param":[
-                   "s-h",
-                   "ch",
-                   "t0"
-                ],
+                "thermostat:set_param":{
+                  "topic":"s-h",
+                  "field":"t0"
+                },
                 "lock":false
              },
              {
@@ -164,11 +158,10 @@
                 "step":1,
                 "siPrefix":true,
                 "suffix":"Ω",
-                "param":[
-                   "s-h",
-                   "ch",
-                   "r0"
-                ],
+                "thermostat:set_param":{
+                  "topic":"s-h",
+                  "field":"r0"
+                },
                 "lock":false
              },
              {
@@ -178,22 +171,20 @@
                 "step":1,
                 "suffix":"K",
                 "decimals":4,
-                "param":[
-                   "s-h",
-                   "ch",
-                   "b"
-                ],
+                "thermostat:set_param":{
+                  "topic":"s-h",
+                  "field":"b"
+                },
                 "lock":false
              },
              {
                 "name":"Postfilter Rate",
                 "type":"list",
                 "value":16.67,
-                "param":[
-                   "postfilter",
-                   "ch",
-                   "rate"
-                ],
+                "thermostat:set_param":{
+                  "topic":"postfilter",
+                  "field":"rate"
+                },
                 "limits":{
                    "Off":null,
                    "16.67 Hz":16.67,
@@ -215,11 +206,10 @@
                 "type":"float",
                 "step":0.1,
                 "suffix":"",
-                "param":[
-                   "pid",
-                   "ch",
-                   "kp"
-                ],
+                "thermostat:set_param":{
+                  "topic":"pid",
+                  "field":"kp"
+                },
                 "lock":false
              },
              {
@@ -227,11 +217,10 @@
                 "type":"float",
                 "step":0.1,
                 "suffix":"Hz",
-                "param":[
-                   "pid",
-                   "ch",
-                   "ki"
-                ],
+                "thermostat:set_param":{
+                  "topic":"pid",
+                  "field":"ki"
+                },
                 "lock":false
              },
              {
@@ -239,11 +228,10 @@
                 "type":"float",
                 "step":0.1,
                 "suffix":"s",
-                "param":[
-                   "pid",
-                   "ch",
-                   "kd"
-                ],
+                "thermostat:set_param":{
+                  "topic":"pid",
+                  "field":"kd"
+                },
                 "lock":false
              },
              {
@@ -261,11 +249,10 @@
                       ],
                       "decimals":6,
                       "suffix":"mA",
-                      "param":[
-                         "pid",
-                         "ch",
-                         "output_min"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pid",
+                        "field":"output_min"
+                      },
                       "lock":false
                    },
                    {
@@ -278,11 +265,10 @@
                       ],
                       "decimals":6,
                       "suffix":"mA",
-                      "param":[
-                         "pid",
-                         "ch",
-                         "output_max"
-                      ],
+                      "thermostat:set_param":{
+                        "topic":"pid",
+                        "field":"output_max"
+                      },
                       "lock":false
                    }
                 ]
diff --git a/pytec/tec_qt.py b/pytec/tec_qt.py
index 2e60e1d..bb9f60e 100644
--- a/pytec/tec_qt.py
+++ b/pytec/tec_qt.py
@@ -267,20 +267,21 @@ class MainWindow(QtWidgets.QMainWindow):
         for inner_param, change, data in changes:
             if change == "value":
                 new_value = data
-                if "param" in inner_param.opts:
+                if "thermostat:set_param" in inner_param.opts:
                     if inner_param.opts.get("suffix", None) == "mA":
                         new_value /= 1000  # Given in mA
 
-                    thermostat_param = inner_param.opts["param"]
-                    if thermostat_param[1] == "ch":
-                        thermostat_param[1] = ch
+                    thermostat_param = inner_param.opts["thermostat:set_param"]
 
                     if inner_param.name() == "Postfilter Rate" and new_value is None:
-                        set_param_args = (*thermostat_param[:2], "off")
-                    else:
-                        set_param_args = (*thermostat_param, new_value)
+                        thermostat_param = thermostat_param.copy()
+                        thermostat_param["field"] = "off"
+                        new_value = ""
+
                     inner_param.setOpts(lock=True)
-                    await self.client.set_param(*set_param_args)
+                    await self.client.set_param(
+                        channel=ch, value=new_value, **thermostat_param
+                    )
                     inner_param.setOpts(lock=False)
 
                 if "pid_autotune" in inner_param.opts: