diff --git a/ModbusThermometer.cpp b/ModbusThermometer.cpp
index f3125bf..de104a2 100644
--- a/ModbusThermometer.cpp
+++ b/ModbusThermometer.cpp
@@ -1,36 +1,52 @@
 #include "Arduino.h"
 
-// #include "Streaming.h"
 #include "Metro.h"
 
 #include "ads1210.h"
 #include "led.h"
-
+#include "SimpleModbusSlave.h"
 
 const uint8_t LED_PIN = 8;
 const uint8_t ADC_CS_PIN = 9;
 const uint8_t ADC_RDY_PIN = 7;
-
+const uint8_t MODBUS_TX_ENABLE_PIN = 6;
+const uint8_t MODBUS_ID = 3;
 
 ADS1210 ads1210;
 LED led;
 Metro secondTick = Metro(1000);
+uint32_t uptimeSeconds;
 
 
-void setup() {
-  // Serial.begin(9600);
-  delay(1000);
-  
+struct {
+	union {
+		uint32_t in;
+		uint16_t modbusRegisters[2]; // 0, 1
+	} adcValue;
+	union {
+		uint32_t in;
+		uint16_t modbusRegisters[2]; // 2, 3
+	} uptimeSeconds;
+} modbusHoldingRegisters;
+
+
+void setup() {  
   led.begin(LED_PIN);
   ads1210.begin(ADC_CS_PIN, ADC_RDY_PIN);
+  modbus_configure(&Serial, 1200, SERIAL_8N2, MODBUS_ID, MODBUS_TX_ENABLE_PIN, 
+                   sizeof(modbusHoldingReigsre), modbusHoldingRegisters)
+  uptimeSeconds = 0;
 }
 
 void loop() {
+  modbus_update();
+
   ads1210.exec();
-  
+  modbusHoldingRegisters.adcValue.in = ads1210.value;
+
   if (secondTick.check() == 1) {
     led.toggle();
-
-    // Serial << "AdcValue: " << _HEX(ads1210.value) << endl;
+	uptimeSeconds++;
+	modbusHoldingRegisters.uptimeSeconds.in = uptimeSeconds;
   }
 }