diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-basic-config/modbus-basic-config.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-basic-config/modbus-basic-config.component.ts
index e85d9d31c0..8291558b4d 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-basic-config/modbus-basic-config.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-basic-config/modbus-basic-config.component.ts
@@ -22,7 +22,6 @@ import {
   FormGroup,
   NG_VALIDATORS,
   NG_VALUE_ACCESSOR,
-  UntypedFormControl,
   ValidationErrors,
   Validator,
 } from '@angular/forms';
@@ -95,6 +94,7 @@ export class ModbusBasicConfigComponent implements ControlValueAccessor, Validat
       .subscribe(enable => {
         this.updateSlaveEnabling(enable);
         this.basicFormGroup.get('slave').updateValueAndValidity({emitEvent: !!this.onChange});
+        this.basicFormGroup.get('master').updateValueAndValidity({emitEvent: !!this.onChange});
       });
   }
 
@@ -121,16 +121,10 @@ export class ModbusBasicConfigComponent implements ControlValueAccessor, Validat
     this.enableSlaveControl.setValue(!!basicConfig.slave && !isEqual(basicConfig.slave, {}));
   }
 
-  validate(basicConfigControl: UntypedFormControl): ValidationErrors | null {
-    const masterHasSlaves = !!basicConfigControl.value.master?.slaves?.length;
-    const slaveEnabled = this.enableSlaveControl.value;
-    const slaveIsValid = this.basicFormGroup.valid;
-
-    if ((slaveEnabled && slaveIsValid) || (masterHasSlaves && !slaveEnabled)) {
-      return null;
-    }
-
-    return { basicFormGroup: { valid: false } };
+  validate(): ValidationErrors | null {
+    return this.basicFormGroup.valid ? null : {
+      basicFormGroup: {valid: false}
+    };
   }
 
   private updateSlaveEnabling(isEnabled: boolean): void {
diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-master-table/modbus-master-table.component.ts b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-master-table/modbus-master-table.component.ts
index 5838540d65..5f51f59284 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-master-table/modbus-master-table.component.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/gateway/connectors-configuration/modbus/modbus-master-table/modbus-master-table.component.ts
@@ -34,8 +34,12 @@ import {
   ControlValueAccessor,
   FormArray,
   FormBuilder,
+  NG_VALIDATORS,
   NG_VALUE_ACCESSOR,
+  UntypedFormControl,
   UntypedFormGroup,
+  ValidationErrors,
+  Validator,
 } from '@angular/forms';
 import {
   ModbusMasterConfig,
@@ -58,12 +62,17 @@ import { TbTableDatasource } from '@shared/components/table/table-datasource.abs
       provide: NG_VALUE_ACCESSOR,
       useExisting: forwardRef(() => ModbusMasterTableComponent),
       multi: true
+    },
+    {
+      provide: NG_VALIDATORS,
+      useExisting: forwardRef(() => ModbusMasterTableComponent),
+      multi: true
     }
   ],
   standalone: true,
   imports: [CommonModule, SharedModule]
 })
-export class ModbusMasterTableComponent implements ControlValueAccessor, AfterViewInit, OnInit, OnDestroy {
+export class ModbusMasterTableComponent implements ControlValueAccessor, Validator, AfterViewInit, OnInit, OnDestroy {
 
   @ViewChild('searchInput') searchInputField: ElementRef;
 
@@ -130,6 +139,12 @@ export class ModbusMasterTableComponent implements ControlValueAccessor, AfterVi
     this.pushDataAsFormArrays(master.slaves);
   }
 
+  validate(masterControl: UntypedFormControl): ValidationErrors | null {
+    return masterControl.parent.get('slave').enabled || this.slaves.controls.length ? null : {
+      slavesFormGroup: {valid: false}
+    };
+  }
+
   enterFilterMode(): void {
     this.textSearchMode = true;
     this.cdr.detectChanges();