diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index cfb7219..29e7074 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -579,6 +579,12 @@ bool DCCEXParser::parseZ(Print *stream, int16_t params, int16_t p[])
         return true;
 
     case 3: // <Z ID PIN INVERT>
+        if (p[0] < 0)
+	  return false;
+	if (p[1] > 255 || p[1] < 0)
+	  return false;
+	if (!(p[2] == 0 || p[2] == 1))
+	  return false;
         if (!Output::create(p[0], p[1], p[2], 1))
           return false;
         StringFormatter::send(stream, F("<O>\n"));
diff --git a/Outputs.cpp b/Outputs.cpp
index b7aa7bc..1e13807 100644
--- a/Outputs.cpp
+++ b/Outputs.cpp
@@ -100,14 +100,14 @@ void  Output::activate(int s){
 
 ///////////////////////////////////////////////////////////////////////////////
 
-Output* Output::get(int n){
+Output* Output::get(uint16_t n){
   Output *tt;
   for(tt=firstOutput;tt!=NULL && tt->data.id!=n;tt=tt->nextOutput);
   return(tt);
 }
 ///////////////////////////////////////////////////////////////////////////////
 
-bool Output::remove(int n){
+bool Output::remove(uint16_t n){
   Output *tt,*pp=NULL;
 
   for(tt=firstOutput;tt!=NULL && tt->data.id!=n;pp=tt,tt=tt->nextOutput);
@@ -160,7 +160,7 @@ void Output::store(){
 }
 ///////////////////////////////////////////////////////////////////////////////
 
-Output *Output::create(int id, int pin, int iFlag, int v){
+Output *Output::create(uint16_t id, uint8_t pin, uint8_t iFlag, uint8_t v){
   Output *tt;
 
   if(firstOutput==NULL){
diff --git a/Outputs.h b/Outputs.h
index 319f704..a0431e0 100644
--- a/Outputs.h
+++ b/Outputs.h
@@ -23,25 +23,27 @@
 
 struct OutputData {
   uint8_t oStatus;
-  uint8_t id;
+  uint16_t id;
   uint8_t pin; 
   uint8_t iFlag; 
 };
 
 class Output{
-  public:
+
+public:
   void activate(int s);
-  static Output* get(int);
-  static bool remove(int);
+  static Output* get(uint16_t);
+  static bool remove(uint16_t);
   static void load();
   static void store();
-  static Output *create(int, int, int, int=0);
+  static Output *create(uint16_t, uint8_t, uint8_t, uint8_t=0);
   static Output *firstOutput;
   struct OutputData data;
   Output *nextOutput;
   static void printAll(Print *);
-  private:
-  int num;  // Chris has no idea what this is all about!
+
+private:
+  int num;  // EEPROM pointer (Chris has no idea what this is all about!)
   
 }; // Output
   
diff --git a/version.h b/version.h
index 9b926cd..97e34c7 100644
--- a/version.h
+++ b/version.h
@@ -3,7 +3,8 @@
 
 #include "StringFormatter.h"
 
-#define VERSION "3.1.4"
+#define VERSION "3.1.5"
+// 3.1.5 Make output ID two bytes
 // 3.1.4 Refactor OLED and LCD drivers and remove unused code
 // 3.1.3 Add a loop delay to give more time for sensing an Ethernet cable connection
 // 3.1.2 Eliminate wait after write when prog is joined or prog power is off