diff --git a/controllers/modbus.controller.js b/controllers/modbus.controller.js
index 9f34f9b..3305220 100644
--- a/controllers/modbus.controller.js
+++ b/controllers/modbus.controller.js
@@ -224,7 +224,7 @@ export const modbusController = {
       const streamInterval = setInterval(async () => {
         try {
           device.display_values = await db.all(`SELECT * FROM "display_values" WHERE slave_id = ?`, [slave_id]) 
-          const data = await modbusService.readDataFromDevice(device, device.g_display_reg_type);
+          const data = await modbusService.readDataFromDevice(device);
           res.write("event: message\n");
           res.write(`data: ${JSON.stringify(data)}\n\n`);
         } catch (error) {
diff --git a/data.db b/data.db
index 9790eae..76368a9 100644
Binary files a/data.db and b/data.db differ
diff --git a/index.d.ts b/index.d.ts
index 5e81d19..f5b8b77 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -30,4 +30,9 @@ export type ModbusDevice = {
   g_y_label: string | null;
   is_logging: boolean;
   display_values?: DisplayValue[]
+}
+
+export type EventDataStream = {
+  graph: { value: number; format: NumberType } | null;
+  displayValues: DisplayValue[];
 }
\ No newline at end of file
diff --git a/migrations/001-init.sql b/migrations/001-init.sql
index 1cc312b..073ba83 100644
--- a/migrations/001-init.sql
+++ b/migrations/001-init.sql
@@ -22,7 +22,7 @@ CREATE TABLE IF NOT EXISTS "modbus_slaves" (
 	"id" INTEGER CHECK (id >= 1 AND id <= 255),
 	"name" VARCHAR(256) NOT NULL,
 	"g_display_reg_addr" INTEGER CHECK(g_display_reg_addr >= 0 AND g_display_reg_addr <= 65534) DEFAULT NULL, 
-	"g_display_reg_type" VARCHAR(3) CHECK(g_display_reg_type IN("HR", "IR")) DEFAULT "HR",
+	"g_display_reg_type" VARCHAR(3) CHECK(g_display_reg_type IN("HR", "IR")) DEFAULT "IR",
 	"g_display_reg_format" VARCHAR(5) CHECK(g_display_reg_format IN("UI16", "I16", "UI32", "I32", "FP32")) DEFAULT "UI16",
 	"g_y_label" VARCHAR(40) DEFAULT "Label",
 	"is_logging" BOOLEAN NOT NULL DEFAULT FALSE,
@@ -34,6 +34,7 @@ CREATE TABLE IF NOT EXISTS "display_values" (
 	"name" VARCHAR(32) NOT NULL,
 	"slave_id" INTEGER NOT NULL,
 	"reg_addr" INTEGER DEFAULT 0 NOT NULL CHECK(reg_addr >= 0 AND reg_addr <= 65534),
+	-- "reg_type" VARCHAR(3) CHECK(reg_type IN("HR", "IR", "DI", "DO")) DEFAULT "IR",
 	"reg_format" INTEGER NOT NULL CHECK(reg_format IN(16, 32)) DEFAULT 16,
 	PRIMARY KEY("id"),
 	FOREIGN KEY("slave_id") REFERENCES modbus_slaves("id") ON DELETE CASCADE
diff --git a/public/js/app.js b/public/js/app.js
index e0f7a46..0142c7a 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -148,7 +148,7 @@ document.addEventListener("alpine:init", async () => {
       }
       dataStreamSource.onmessage = (e) => {
         const data = JSON.parse(e.data);
-
+        console.log('[SSE Message]', data);
         if (data.graph !== null) {
           graphData.push([new Date(), data.graph.value]);
           if (g === null) {
diff --git a/services/modbus.service.js b/services/modbus.service.js
index 159ca46..f66c419 100644
--- a/services/modbus.service.js
+++ b/services/modbus.service.js
@@ -4,36 +4,65 @@ import * as utils from '#root/utils/index.js'
 export const modbusService = {
   /**
    * @param {import("..").ModbusDevice} device
-   * @param {"HR" | "IR"} type
+   * @return {Promise<import("..").EventDataStream>}
    */
-  async readDataFromDevice(device, type = 'HR') {
-    const { g_display_reg_format: g_format, g_display_reg_addr: g_reg_addr } = device;
-    let readLength = 1; // 16 bits default
+  async readDataFromDevice(device) {
+    const { g_display_reg_format, g_display_reg_addr, g_display_reg_type } = device;
+    
+    /** @type {import("..").EventDataStream} */
+    const data = { graph: null, displayValues: [] };
 
     modbusClient.setID(device.id);
-
-    if (g_format?.includes('32')) readLength = 2;
-    if (g_format?.includes('64')) readLength = 4;
-    if (g_format?.includes('128')) readLength = 8;
     
-    let graphValue;
-    if (type === 'HR') graphValue = await modbusClient.readHoldingRegisters(g_reg_addr, readLength);
-    if (type === 'IR') graphValue = await modbusClient.readInputRegisters(g_reg_addr, readLength);
+    /* Read data for graph */
+    if (g_display_reg_addr !== null) {
+      const graphValue = await this.readModbusRegisters(g_display_reg_addr, g_display_reg_type, g_display_reg_format);
+      data.graph = {
+        value: utils.readNumberFromBuf(graphValue, device.g_display_reg_format, 'BE'),
+        format: g_display_reg_format
+      }
+    }
 
+    /* Read data for display values */
     if (device.display_values) {
       for (const value of device.display_values) {
-        value.data = Buffer.from((await modbusClient.readHoldingRegisters(value.reg_addr, 1)).buffer).readUInt16BE();
-      }      
+        value.data = Buffer.from((await this.readModbusRegisters(value.reg_addr, 'HR', 'UI16'))).readUInt16BE();
+      }
     }
 
-    const graph = (g_reg_addr !== null ?  {
-        value: utils.readNumberFromBuf(graphValue.buffer, device.g_display_reg_format, 'BE'),
-        format: g_format
-      } : null);
+    data.displayValues = device.display_values;
 
-    return {
-      graph,
-      displayValues: device.display_values
+    return data;
+  },
+
+  /**
+   * @param {number} addr
+   * @param {"HR" | "IR" | "DI"} type
+   * @param {import("..").NumberType} format
+   * @return {Promise<Buffer>} buffer data
+   */
+  async readModbusRegisters(addr, type, format) {
+    let data;
+    let len = 1;
+  
+    if (format.includes('32')) len = 2;
+    if (format.includes('64')) len = 4;
+    if (format.includes('128')) len = 8;
+  
+    switch (type) {
+      case 'HR':
+        data = await modbusClient.readHoldingRegisters(addr, len);  
+        break;
+      case 'IR':
+        data = await modbusClient.readInputRegisters(addr, len);
+        break;
+      case 'DI':
+        data = await modbusClient.readDiscreteInputs(addr, len);
+        break;
+      default:
+        throw new Error('Incorrect modbus register type!');
     }
+  
+    return data.buffer;
   }
 }
\ No newline at end of file