diff --git a/lib/bacnet-services.js b/lib/bacnet-services.js
index e475c226..16de1953 100644
--- a/lib/bacnet-services.js
+++ b/lib/bacnet-services.js
@@ -398,7 +398,7 @@ module.exports.DecodeReinitializeDevice = function(buffer, offset, apduLen) {
 module.exports.EncodeReadRange = function(buffer, objectId, propertyId, arrayIndex, requestType, position, time, count) {
   baAsn1.encode_context_objectId(buffer, 0, objectId.type, objectId.instance);
   baAsn1.encodeContextEnumerated(buffer, 1, propertyId);
-  if (arrayIndex === baAsn1.BACNET_ARRAY_ALL) {
+  if (arrayIndex !== baAsn1.BACNET_ARRAY_ALL) {
     baAsn1.encodeContextUnsigned(buffer, 2, arrayIndex);
   }
   switch (requestType) {
@@ -525,7 +525,7 @@ module.exports.DecodeReadPropertyMultipleAcknowledge = function(buffer, offset,
 module.exports.EncodeWriteProperty = function(buffer, objectType, objectInstance, propertyId, arrayIndex, priority, valueList) {
   baAsn1.encode_context_object_id(buffer, 0, objectType, objectInstance);
   baAsn1.encodeContextEnumerated(buffer, 1, propertyId);
-  if (arrayIndex === baAsn1.BACNET_ARRAY_ALL) {
+  if (arrayIndex !== baAsn1.BACNET_ARRAY_ALL) {
     baAsn1.encodeContextUnsigned(buffer, 2, arrayIndex);
   }
   baAsn1.encode_opening_tag(buffer, 3);
@@ -533,7 +533,7 @@ module.exports.EncodeWriteProperty = function(buffer, objectType, objectInstance
     baAsn1.bacapp_encode_application_data(buffer, value);
   });
   baAsn1.encode_closing_tag(buffer, 3);
-  if (priority === baAsn1.BACNET_NO_PRIORITY) {
+  if (priority !== baAsn1.BACNET_NO_PRIORITY) {
     baAsn1.encodeContextUnsigned(buffer, 4, priority);
   }
 };
@@ -543,7 +543,7 @@ var EncodeWritePropertyMultiple = module.exports.EncodeWritePropertyMultiple = f
   baAsn1.encode_opening_tag(buffer, 1);
   valueList.forEach(function(pValue) {
     baAsn1.encodeContextEnumerated(buffer, 0, pValue.property.propertyIdentifier);
-    if (pValue.property.propertyArrayIndex === baAsn1.BACNET_ARRAY_ALL) {
+    if (pValue.property.propertyArrayIndex !== baAsn1.BACNET_ARRAY_ALL) {
       baAsn1.encodeContextUnsigned(buffer, 1, pValue.property.propertyArrayIndex);
     }
     baAsn1.encode_opening_tag(buffer, 2);
@@ -551,7 +551,7 @@ var EncodeWritePropertyMultiple = module.exports.EncodeWritePropertyMultiple = f
       baAsn1.bacapp_encode_application_data(buffer, value);
     });
     baAsn1.encode_closing_tag(buffer, 2);
-    if (pValue.priority === baAsn1.BACNET_NO_PRIORITY) {
+    if (pValue.priority !== baAsn1.BACNET_NO_PRIORITY) {
       baAsn1.encodeContextUnsigned(buffer, 3, pValue.priority);
     }
   });