diff --git a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/driver/OpcDeviceDriver.java b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/driver/OpcDeviceDriver.java
index c1d27c02a..04fbae0a4 100644
--- a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/driver/OpcDeviceDriver.java
+++ b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/driver/OpcDeviceDriver.java
@@ -190,7 +190,7 @@ public interface OpcDeviceDriver extends DeviceDriver {
      * @return
      */
     default String getStringValue(String protocol) {
-        return this.getOpcValueAccessor().getValue(this.getItem(protocol)).toString();
+        return (String) this.getOpcValueAccessor().getValue(this.getItem(protocol));
     }
 
     /**
diff --git a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/one_conveyor/box_subvolumes_conveyor/ItemProtocol.java b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/one_conveyor/box_subvolumes_conveyor/ItemProtocol.java
index 56a2e5c48..8b81241be 100644
--- a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/one_conveyor/box_subvolumes_conveyor/ItemProtocol.java
+++ b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/device_driver/one_conveyor/box_subvolumes_conveyor/ItemProtocol.java
@@ -153,7 +153,7 @@ public class ItemProtocol {
         } else {
             return value;
         }
-        return "0";
+        return "";
     }
 
     public static List<ItemDto> getReadableItemDtos() {
diff --git a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/opc/DeviceOpcProtocolRunable.java b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/opc/DeviceOpcProtocolRunable.java
index 1f245e4c4..8e8f2f0ba 100644
--- a/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/opc/DeviceOpcProtocolRunable.java
+++ b/acs2/nladmin-system/nlsso-server/src/main/java/org/nl/acs/opc/DeviceOpcProtocolRunable.java
@@ -207,10 +207,8 @@ public class DeviceOpcProtocolRunable implements Runnable, DataCallback, ServerC
 
                         if (!UnifiedDataAppService.isEquals(value, his)) {
                             OpcItemDto itemDto = this.getItem(itemId);
-                            if (true) {
-                                this.logItemChanged(itemId, accessor_value, value, itemDto);
-                            }
                             if (!ObjectUtil.isEmpty(value)) {
+                                this.logItemChanged(itemId, accessor_value, value, itemDto);
                                 accessor_value.setValue(itemId, value);
                             }
                         }
@@ -436,7 +434,6 @@ public class DeviceOpcProtocolRunable implements Runnable, DataCallback, ServerC
                         String.valueOf(itemDto.getHis_item_value()), String.valueOf(itemDto.getItem_value()));
                 luceneLogDto.setLogType(LogTypeEnum.DEVICE_LOG.getDesc());
                 log.info("{}", JSON.toJSONString(luceneLogDto));
-
             }
         } else {
             if(his instanceof int[]){