diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-data-keys-panel/modbus-data-keys-panel.component.scss b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-data-keys-panel/modbus-data-keys-panel.component.scss
index d9ef45d66b..445ac6c0ae 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-data-keys-panel/modbus-data-keys-panel.component.scss
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-data-keys-panel/modbus-data-keys-panel.component.scss
@@ -20,7 +20,7 @@
     max-width: 700px;
 
     .title-container {
-      width: 12vw;
+      width: 180px;
     }
 
     .key-panel {
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.html b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.html
index d37c8cc9ee..12ddb479ca 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.html
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.html
@@ -161,7 +161,7 @@
       </div>
     </div>
     <div class="tb-form-row column-xs" fxLayoutAlign="space-between center">
-      <div class="fixed-title-width" translate>gateway.poll-period</div>
+      <div class="fixed-title-width tb-required" translate>gateway.poll-period</div>
       <div class="tb-flex no-gap">
         <mat-form-field class="tb-flex no-gap" appearance="outline" subscriptSizing="dynamic">
           <input matInput type="number" min="0" name="value" formControlName="pollPeriod" placeholder="{{ 'gateway.set' | translate }}"/>
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.ts
index 2a8488a2d4..d0e8ecdd4e 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-config/modbus-slave-config.component.ts
@@ -106,11 +106,11 @@ export class ModbusSlaveConfigComponent implements ControlValueAccessor, Validat
       port: [null, [Validators.required, Validators.min(PortLimits.MIN), Validators.max(PortLimits.MAX)]],
       serialPort: ['', [Validators.required, Validators.pattern(noLeadTrailSpacesRegex)]],
       method: [ModbusMethodType.SOCKET],
-      unitId: [0, [Validators.required]],
+      unitId: [null, [Validators.required]],
       baudrate: [this.modbusBaudrates[0]],
       deviceName: ['', [Validators.required, Validators.pattern(noLeadTrailSpacesRegex)]],
       deviceType: ['', [Validators.required, Validators.pattern(noLeadTrailSpacesRegex)]],
-      pollPeriod: [5000],
+      pollPeriod: [5000, [Validators.required]],
       sendDataToThingsBoard: [false],
       byteOrder:[ModbusOrderType.BIG],
       security: [],
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.html b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.html
index c7fb50f146..088b385623 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.html
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.html
@@ -306,7 +306,7 @@
                 </mat-slide-toggle>
               </div>
               <div class="tb-form-row column-xs" fxLayoutAlign="space-between center">
-                <div class="fixed-title-width-230" translate>gateway.poll-period</div>
+                <div class="fixed-title-width-230 tb-required" translate>gateway.poll-period</div>
                 <div class="tb-flex no-gap">
                   <mat-form-field class="tb-flex no-gap" appearance="outline" subscriptSizing="dynamic">
                     <input matInput type="number" min="0" name="value" formControlName="pollPeriod" placeholder="{{ 'gateway.set' | translate }}"/>
@@ -314,7 +314,7 @@
                 </div>
               </div>
               <div class="tb-form-row column-xs" fxLayoutAlign="space-between center">
-                <div class="fixed-title-width-230" translate>gateway.connect-attempt-time</div>
+                <div class="fixed-title-width-230 tb-required" translate>gateway.connect-attempt-time</div>
                 <div class="tb-flex no-gap">
                   <mat-form-field class="tb-flex no-gap" appearance="outline" subscriptSizing="dynamic">
                     <input matInput type="number" min="0" name="value" formControlName="connectAttemptTimeMs" placeholder="{{ 'gateway.set' | translate }}"/>
@@ -322,7 +322,7 @@
                 </div>
               </div>
               <div class="tb-form-row column-xs" fxLayoutAlign="space-between center">
-                <div class="fixed-title-width-230" translate>gateway.connect-attempt-count</div>
+                <div class="fixed-title-width-230 tb-required" translate>gateway.connect-attempt-count</div>
                 <div class="tb-flex no-gap">
                   <mat-form-field class="tb-flex no-gap" appearance="outline" subscriptSizing="dynamic">
                     <input matInput type="number" min="0" name="value" formControlName="connectAttemptCount" placeholder="{{ 'gateway.set' | translate }}"/>
@@ -330,7 +330,7 @@
                 </div>
               </div>
               <div class="tb-form-row column-xs" fxLayoutAlign="space-between center">
-                <div class="fixed-title-width-230" translate>gateway.wait-after-failed-attempts</div>
+                <div class="fixed-title-width-230 tb-required" translate>gateway.wait-after-failed-attempts</div>
                 <div class="tb-flex no-gap">
                   <mat-form-field class="tb-flex no-gap" appearance="outline" subscriptSizing="dynamic">
                     <input matInput type="number" min="0" name="value" formControlName="waitAfterFailedAttemptsMs" placeholder="{{ 'gateway.set' | translate }}"/>
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.ts
index a00a488aa0..e21a9921a7 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-slave-dialog/modbus-slave-dialog.component.ts
@@ -163,7 +163,7 @@ export class ModbusSlaveDialogComponent extends DialogComponent<ModbusSlaveDialo
       bytesize: [ModbusByteSizes[0]],
       parity: [ModbusParity.None],
       strict: [true],
-      unitId: [0, [Validators.required]],
+      unitId: [null, [Validators.required]],
       deviceName: ['', [Validators.required, Validators.pattern(noLeadTrailSpacesRegex)]],
       deviceType: ['', [Validators.required, Validators.pattern(noLeadTrailSpacesRegex)]],
       sendDataOnlyOnChange: [false],
@@ -173,10 +173,10 @@ export class ModbusSlaveDialogComponent extends DialogComponent<ModbusSlaveDialo
       retries: [true],
       retryOnEmpty: [true],
       retryOnInvalid: [true],
-      pollPeriod: [5000],
-      connectAttemptTimeMs: [5000],
-      connectAttemptCount: [5],
-      waitAfterFailedAttemptsMs: [300000],
+      pollPeriod: [5000, [Validators.required]],
+      connectAttemptTimeMs: [5000, [Validators.required]],
+      connectAttemptCount: [5, [Validators.required]],
+      waitAfterFailedAttemptsMs: [300000, [Validators.required]],
       values: [{}],
       security: [{}],
     });