diff --git a/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.cpp b/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.cpp
new file mode 100644
index 0000000..11f5cb1
--- /dev/null
+++ b/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.cpp
@@ -0,0 +1,145 @@
+#include <DigitalOutputRTU.hpp>
+DigitalOutputRTU::DigitalOutputRTU()
+{
+    // constructor implementation
+}
+
+DigitalOutputRTU::~DigitalOutputRTU()
+{
+    // destructor implementation
+}
+
+void DigitalOutputRTU::begin(char *remoteBaseTopic, uint8_t remote_card_slot, ESPMegaIoT *iot)
+{
+    // begin implementation
+    this->remoteBaseTopic = remoteBaseTopic;
+    this->remoteBaseTopicLength = strlen(remoteBaseTopic);
+    this->cardSlot = remote_card_slot;
+    this->iot = iot;
+
+}
+
+void DigitalOutputRTU::subscribe()
+{
+    // Subscribe to all pins
+    // State Topic format: <base_topic>/<card_slot>/<pin>/state
+    // Value Topic format: <base_topic>/<card_slot>/<pin>/value
+    char buffer[100];
+    for (uint8_t i = 0; i < 16; i++)
+    {
+        sprintf(buffer, "%s/%02d/%02d/state", this->remoteBaseTopic, this->cardSlot, i);
+        this->iot->subscribe(buffer);
+        sprintf(buffer, "%s/%02d/%02d/value", this->remoteBaseTopic, this->cardSlot, i);
+        this->iot->subscribe(buffer);
+    }
+}
+
+void DigitalOutputRTU::digitalWrite(uint8_t pin, bool state)
+{
+    // Publish state to topic <base_topic>/<card_slot>/<pin>/set/state
+    // Publish 4095 to topic <base_topic>/<card_slot>/<pin>/set/value
+    char buffer[100];
+    sprintf(buffer, "%s/%02d/%02d/set/state", this->remoteBaseTopic, this->cardSlot, pin);
+    this->iot->publish(buffer, state ? "1" : "0");
+    sprintf(buffer, "%s/%02d/%02d/set/value", this->remoteBaseTopic, this->cardSlot, pin);
+    this->iot->publish(buffer, "4095");
+}
+
+void DigitalOutputRTU::analogWrite(uint8_t pin, uint16_t value)
+{
+    // Publish 1 to topic <base_topic>/<card_slot>/<pin>/set/state
+    // Publish value to topic <base_topic>/<card_slot>/<pin>/set/value
+    char buffer[100];
+    sprintf(buffer, "%s/%02d/%02d/set/state", this->remoteBaseTopic, this->cardSlot, pin);
+    this->iot->publish(buffer, "1");
+    sprintf(buffer, "%s/%02d/%02d/set/value", this->remoteBaseTopic, this->cardSlot, pin);
+    char valueBuffer[10];
+    itoa(value, valueBuffer, 10);
+    this->iot->publish(buffer, valueBuffer);
+}
+
+void DigitalOutputRTU::setState(uint8_t pin, bool state)
+{
+    // Publish state to topic <base_topic>/<card_slot>/<pin>/set/state
+    char buffer[100];
+    sprintf(buffer, "%s/%02d/%02d/set/state", this->remoteBaseTopic, this->cardSlot, pin);
+    this->iot->publish(buffer, state ? "1" : "0");
+}
+
+void DigitalOutputRTU::setValue(uint8_t pin, uint16_t value)
+{
+    // Publish value to topic <base_topic>/<card_slot>/<pin>/set/value
+    char buffer[100];
+    sprintf(buffer, "%s/%02d/%02d/set/value", this->remoteBaseTopic, this->cardSlot, pin);
+    char valueBuffer[10];
+    itoa(value, valueBuffer, 10);
+    this->iot->publish(buffer, valueBuffer);
+}
+
+bool DigitalOutputRTU::getState(uint8_t pin)
+{
+    return this->outputStateBuffer[pin];
+}
+
+uint16_t DigitalOutputRTU::getValue(uint8_t pin)
+{
+    return this->outputValueBuffer[pin];
+}
+
+uint8_t DigitalOutputRTU::registerChangeCallback(std::function<void(uint8_t, bool, uint16_t)> callback)
+{
+    this->change_callbacks[callbackCount] = callback;
+    return callbackCount++;
+}
+
+void DigitalOutputRTU::unregisterChangeCallback(uint8_t handler)
+{
+    this->change_callbacks.erase(handler);
+}
+
+void DigitalOutputRTU::mqttCallback(char *topic, char *payload) {
+    // First trim base topic from topic
+    char* topicWithoutBase = topic + this->remoteBaseTopicLength;
+    // Then check if topic is in format /<cardSlot>/<pin>/state or /<cardSlot>/<pin>/value
+    // Example trimmed topic: /01/00/state, /01/00/value
+    // Card slot range from 00 to 99
+    // Pin range from 00 to 15
+    // Note that both card and pin are padded with 0 if they are less than 10
+    if(strlen(topicWithoutBase) != 12)
+        return;
+    if(topicWithoutBase[0] != '/')
+        return;
+    if(topicWithoutBase[3] != '/')
+        return;
+    if(topicWithoutBase[6] != '/')
+        return;
+    // Extract card slot and pin
+    uint8_t cardSlot = (topicWithoutBase[1] - '0') * 10 + (topicWithoutBase[2] - '0');
+    // Check if card slot is correct
+    if(cardSlot != this->cardSlot)
+        return;
+    uint8_t pin = (topicWithoutBase[4] - '0') * 10 + (topicWithoutBase[5] - '0');
+    // Extract value
+    uint16_t value = atoi(payload);
+    // Is it state or value?
+    if(!strcmp(topicWithoutBase + 7, "state"))
+    {
+        // Update state buffer
+        this->outputStateBuffer[pin] = strcmp(payload, "1") == 0;
+        // Call callbacks
+        for(auto const& callback : this->change_callbacks)
+        {
+            callback.second(pin, this->outputStateBuffer[pin], this->outputValueBuffer[pin]);
+        }
+    }
+    else if(!strcmp(topicWithoutBase + 7, "value"))
+    {
+        // Update value buffer
+        this->outputValueBuffer[pin] = value;
+        // Call callbacks
+        for(auto const& callback : this->change_callbacks)
+        {
+            callback.second(pin, this->outputStateBuffer[pin], this->outputValueBuffer[pin]);
+        }
+    }
+}
\ No newline at end of file
diff --git a/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.hpp b/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.hpp
new file mode 100644
index 0000000..d908a04
--- /dev/null
+++ b/ESPMegaPRO-OS-SDK/lib/ESPMegaPRO/DigitalOutputRTU.hpp
@@ -0,0 +1,29 @@
+#pragma once
+#include <ESPMegaRTU.hpp>
+#include <DigitalOutputCard.hpp>
+
+class DigitalOutputRTU : public ESPMegaRTU
+{
+public:
+    DigitalOutputRTU();
+    ~DigitalOutputRTU();
+    void begin(char *remoteBaseTopic, uint8_t remote_card_slot, ESPMegaIoT *iot);
+    void subscribe();
+    void digitalWrite(uint8_t pin, bool state);
+    void analogWrite(uint8_t pin, uint16_t value);
+    void setState(uint8_t pin, bool state);
+    void setValue(uint8_t pin, uint16_t value);
+    bool getState(uint8_t pin);
+    uint16_t getValue(uint8_t pin);
+    uint8_t registerChangeCallback(std::function<void(uint8_t, bool, uint16_t)> callback);
+    void unregisterChangeCallback(uint8_t handler);
+
+private:
+    void mqttCallback(char *topic, char *payload);
+    ESPMegaIoT *iot;
+    size_t size;
+    uint16_t callbackCount;
+    std::map<uint8_t, std::function<void(uint8_t, bool, uint16_t)>> change_callbacks;
+    bool outputStateBuffer[16];
+    uint16_t outputValueBuffer[16];
+};
\ No newline at end of file