diff --git a/controllers/modbus.controller.js b/controllers/modbus.controller.js
index a521f5f..2596b94 100644
--- a/controllers/modbus.controller.js
+++ b/controllers/modbus.controller.js
@@ -1,5 +1,6 @@
 import db from "#root/config/database.config.js";
 import modbusClient from "#root/config/modbus-client.config.js";
+import * as utils from '#root/utils/index.js'
 import { appService, modbusService } from "#root/services/index.js";
 
 export const modbusController = {
@@ -70,7 +71,7 @@ export const modbusController = {
                     "g_display_reg_format",
                     "g_display_reg_type",
                     "g_y_label") 
-                    VALUES (?, ?, ?, ?, ?, ?, ?)`,
+                    VALUES (?, ?, ?, ?, ?, ?)`,
         [id, name, g_display_reg_addr, g_display_reg_format, g_display_reg_type, g_y_label],
       );
       return res.status(200).json({ message: "Device created." });
@@ -80,13 +81,47 @@ export const modbusController = {
   },
 
   /**
-   * Remove modbus slave device
+   * Update modbus slave device
    * @param {import('express').Request} req
    * @param {import('express').Response} res
    * @param {import('express').NextFunction} next
    */
   async updateDevice(req, res, next) {
     try {
+      const { 
+        id,
+        newId,
+        name, 
+        g_display_reg_addr, 
+        g_display_reg_type, 
+        g_display_reg_format, 
+        g_y_label 
+      } = req.body;
+
+      await db.run(`UPDATE "modbus_slaves" SET 
+                    id = ?, 
+                    name = ?,
+                    g_display_reg_addr = NULL,
+                    g_display_reg_type = NULL,
+                    g_display_reg_format = NULL,
+                    g_y_label = NULL
+                    WHERE id = ? `, 
+                    [newId, name, id]);
+      
+      if (g_display_reg_addr !== null && 
+          g_display_reg_type !== null && 
+          g_display_reg_format !== null &&
+          g_y_label !== null
+          ) {
+        await db.run(`UPDATE "modbus_slaves" SET 
+                      g_display_reg_addr = ?,
+                      g_display_reg_type = ?,
+                      g_display_reg_format = ?,
+                      g_y_label = ? WHERE id = ?`, 
+                      [g_display_reg_addr, g_display_reg_type, g_display_reg_format, g_y_label, id]);
+      }
+
+      return res.status(200).json({ message: 'Updated.' })
     } catch (error) {
       next(error);
     }
@@ -152,12 +187,8 @@ export const modbusController = {
    */
   async status(req, res, next) {
     try {
-      res.setHeader("Cache-Control", "no-cache");
-      res.setHeader("Content-Type", "text/event-stream");
-      res.setHeader("Connection", "keep-alive");
-      let intervalId = setInterval(() => {
-        res.write(`event: message\ndata: ${JSON.stringify(modbusClient.isOpen)}\n\n`);
-      }, 500);
+      utils.setSSEHeaders(res);
+      const intervalId = modbusService.startConnectionStatusInterval((status) => res.write(utils.serializeSSEData(status, 'message')))
       req.on("close", () => clearInterval(intervalId));
     } catch (error) {
       next(error);
@@ -180,38 +211,20 @@ export const modbusController = {
       const device = await db.get(`SELECT * FROM "modbus_slaves" WHERE id = ?`, [slave_id]);
       if (!device) return res.status(404).json({ error: { message: "Device not found." } });
 
-      res.setHeader("Cache-Control", "no-cache");
-      res.setHeader("Content-Type", "text/event-stream");
-      res.setHeader("Connection", "keep-alive");
+      utils.setSSEHeaders(res);
 
-      const intervalId = modbusService.startDevicePollInterval(
+      const intervalId = await modbusService.startDevicePollInterval(
         device,
         (data, error) => {
           if (error) {
             next(error);
             return;
           }
-          res.write("event: message\n");
-          res.write(`data: ${JSON.stringify(data)}\n\n`);
+          res.write(utils.serializeSSEData(data, 'message'));
         },
-        1000,
       );
 
       req.on("close", () => clearInterval(intervalId));
-
-      // 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);
-      //     res.write("event: message\n");
-      //     res.write(`data: ${JSON.stringify(data)}\n\n`);
-      //   } catch (error) {
-      //     clearInterval(streamInterval);
-      //     next(error);
-      //   }
-      // }, 1000);
-
-      // req.on("close", () => clearInterval(streamInterval));
     } catch (error) {
       next(error);
     }
diff --git a/data.db b/data.db
index 44fe851..3986657 100644
Binary files a/data.db and b/data.db differ
diff --git a/migrations/001-init.sql b/migrations/001-init.sql
index dc2da23..0feed69 100644
--- a/migrations/001-init.sql
+++ b/migrations/001-init.sql
@@ -14,7 +14,7 @@ CREATE TABLE IF NOT EXISTS "app_config" (
 	"mb_rtu_stop_bits"	INTEGER NOT NULL DEFAULT 1,
 	"log_interval_ms" INTEGER DEFAULT 1000 NOT NULL,
 	CONSTRAINT "id_unique" CHECK(id=0),
-	CONSTRAINT "min_interval_check" CHECK(log_interval_ms >= 1000)
+	CONSTRAINT "min_interval_check" CHECK(log_interval_ms >= 500)
 	PRIMARY KEY("id")
 );
 
@@ -36,7 +36,7 @@ CREATE TABLE IF NOT EXISTS "display_values" (
 	"reg_type" VARCHAR(3) NOT NULL CHECK(reg_type IN("HR", "IR", "DI", "DO")) DEFAULT "IR",
 	"reg_format" VARCHAR(5) NOT NULL CHECK(reg_format IN("UI16", "I16", "UI32", "I32", "FP32", "BOOL")) DEFAULT "UI16",
 	PRIMARY KEY("id"),
-	FOREIGN KEY("slave_id") REFERENCES modbus_slaves("id") ON DELETE CASCADE
+	FOREIGN KEY("slave_id") REFERENCES modbus_slaves("id") ON DELETE CASCADE ON UPDATE CASCADE
 );
 
 -- CREATE TABLE IF NOT EXISTS "modbus_log" (
diff --git a/public/index.html b/public/index.html
index 0933531..b45d452 100644
--- a/public/index.html
+++ b/public/index.html
@@ -46,14 +46,14 @@
                 <template x-teleport="body">
                   <div
                     x-data="deviceModal"
-                    @open-create-device-modal.window="open()"
+                    @open-device-modal.window="open($event)"
                     @keyup.escape.window="close()"
                     class="backdrop z-50"
                     x-show="isOpen"
                   >
                     <div class="modal">
                       <div class="flex justify-between items-center">
-                        <h2 class="font-bold text-lg">Create new device</h2>
+                        <h2 x-text="labels.title" class="font-bold text-lg"></h2>
                         <button @click="close()" aria-label="Close">
                           <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
                             <path
@@ -64,7 +64,7 @@
                         </button>
                       </div>
                       <hr />
-                      <form @submit.prevent="create(() => graphView = 'none')" action="#">
+                      <form @submit.prevent="submit" action="#">
                         <div
                           x-id="['id', 'name', 'graph-display', 'g_display_reg_addr', 'g_display_reg_format', 'g_y_label']"
                           class="flex flex-col space-y-2"
@@ -167,12 +167,12 @@
                           <button
                             x-bind:disabled="isLoading"
                             x-bind:class="isLoading && 'opacity-70'"
+                            x-text="labels.submit"
                             type="submit"
                             class="btn"
                           >
-                            Create
                           </button>
-                          <button @click="close()" class="btn bg-red-500">Cancel</button>
+                          <button x-text="labels.cancel" @click="close()" class="btn bg-red-500"></button>
                         </div>
                       </form>
                     </div>
@@ -180,7 +180,10 @@
                 </template>
                 <!-- Create new device -->
                 <button
-                  @click="$dispatch('open-create-device-modal')"
+                  @click="$dispatch('open-device-modal', { 
+                    labels: { title: 'Create new device', submit: 'Create', cancel: 'Cancel' },
+                    actionType: 'CREATE'
+                   })"
                   class="w-full min-h-[50px] text-center border-2 border-dashed rounded-sm hover:bg-gray-50 cursor-pointer"
                 >
                   <span class="text-4xl text-gray-400 select-none">+</span>
@@ -209,7 +212,13 @@
                   </div>
                   <!-- Device create, delete buttons -->
                   <div>
-                    <a href="#">Edit</a>
+                    <a 
+                      @click="$dispatch('open-device-modal', { 
+                        labels: { title: `Edit device ${selectedDevice?.name}`, submit: 'Save', cancel: 'Cancel' },
+                        device: selectedDevice,
+                        actionType: 'EDIT'
+                      })" 
+                     href="#">Edit</a>
                     <a
                       @click="$dispatch('dialog', { 
                                           title: 'Remove device', 
@@ -569,7 +578,8 @@
                   id="log_interval_ms"
                   name="log_interval_ms"
                   type="number"
-                  min="1000"
+                  min="500"
+                  max="10000"
                   x-model.number="$store.app.config.log_interval_ms"
                   required
                 />
diff --git a/public/js/app.js b/public/js/app.js
index fb76336..88b70ed 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -64,13 +64,20 @@ document.addEventListener("alpine:init", async () => {
     error: null,
     graphView: "",
     data: {
+      oldId: null,
       id: null,
       name: "",
-      g_display_reg_addr: null,
+      g_display_reg_addr: 0,
       g_display_reg_format: "UI16",
       g_display_reg_type: "IR",
       g_y_label: "",
     },
+    labels: {
+      title: '',
+      submit: '',
+      cancel: ''
+    },
+    actionType: 'CREATE',
     resetDataFields() {
       this.data.id = null;
       this.data.name = "";
@@ -95,7 +102,57 @@ document.addEventListener("alpine:init", async () => {
         this.isLoading = false;
       }
     },
-    open() {
+    async edit() {
+      try {
+        this.isLoading = true;
+        this.error = null;
+        if (this.graphView === 'none') {
+          this.data.g_display_reg_addr = null;
+          this.data.g_display_reg_format = null;
+          this.data.g_display_reg_type = null;
+          this.data.g_y_label = null;
+        }
+        await api.post('/modbus/update_device', utils.dellNullableKeys({ ...this.data, id: this.data.oldId, newId: this.data.id }));
+        window.location.reload();
+      } catch (error) {
+        this.error = error;
+        console.error(error);
+      } finally {
+        this.isLoading = false;
+      }
+    },
+    async submit() {
+      switch (this.actionType) {
+        case 'CREATE':
+          await this.create()
+          this.graphView = 'none'
+          break;
+        case 'EDIT':
+          await this.edit()
+          break;
+        default:
+          break;
+      }
+    },
+    open(event) {
+      const { detail } = event;
+      this.labels = { 
+        title: detail.labels.title, 
+        body: detail.labels.body, 
+        submit: detail.labels.submit, 
+        cancel: detail.labels.cancel 
+      };
+      this.actionType = detail.actionType;
+      if (detail.device) {
+        this.data.oldId = detail.device.id;
+        this.data.id = detail.device.id;
+        this.data.name = detail.device.name;
+        this.data.g_display_reg_addr = detail.device.g_display_reg_addr || 0;
+        this.data.g_display_reg_format = detail.device.g_display_reg_format || 'UI16';
+        this.data.g_display_reg_type = detail.device.g_display_reg_type || 'IR';
+        this.data.g_y_label = detail.device.g_y_label || '';
+        if (detail.device.g_display_reg_addr !== null) this.graphView = 'new-value'
+      }
       this.isOpen = true;
     },
     close() {
diff --git a/services/modbus.service.js b/services/modbus.service.js
index ee8655f..6a9fd45 100644
--- a/services/modbus.service.js
+++ b/services/modbus.service.js
@@ -147,9 +147,9 @@ export const modbusService = {
   /**
    * @param {import("..").ModbusDevice} device
    * @param {(data: import("..").EventDataStream, error: any) => void} callback
-   * @param {number} intervalMs
    */
-  startDevicePollInterval(device, callback, intervalMs) {
+  async startDevicePollInterval(device, callback) {
+    const { log_interval_ms: intervalMs } = await db.get(`SELECT "log_interval_ms" FROM "app_config"`);
     const poll = async () => {
       try {
         device.display_values = await db.all(`SELECT * FROM "display_values" WHERE slave_id = ?`, [device.id]);
@@ -161,4 +161,11 @@ export const modbusService = {
     };
     return setInterval(poll, intervalMs);
   },
+
+  /**
+   * @param {(isOpen: boolean) => void} callback
+   */
+  startConnectionStatusInterval(callback) {
+    return setInterval(() => callback(modbusClient.isOpen), 500)
+  } 
 };
diff --git a/utils/http.js b/utils/http.js
new file mode 100644
index 0000000..4c54ccf
--- /dev/null
+++ b/utils/http.js
@@ -0,0 +1,17 @@
+
+/**
+ * @param {import('express').Response} res 
+ */
+export function setSSEHeaders(res) {
+  res.setHeader("Cache-Control", "no-cache");
+  res.setHeader("Content-Type", "text/event-stream");
+  res.setHeader("Connection", "keep-alive");
+}
+
+/**
+ * @param {any} data
+ * @param {string} eventType
+ */
+export function serializeSSEData(data, eventType) {
+  return `event: ${eventType}\ndata: ${JSON.stringify(data)}\n\n`;
+}
\ No newline at end of file
diff --git a/utils/index.js b/utils/index.js
index 23ae8fe..b623ccb 100644
--- a/utils/index.js
+++ b/utils/index.js
@@ -1 +1,2 @@
-export * from './number.js'
\ No newline at end of file
+export * from './number.js'
+export * from './http.js'
\ No newline at end of file
diff --git a/validators/display-value.schema.js b/validators/display-value.schema.js
index 1470801..2230eb6 100644
--- a/validators/display-value.schema.js
+++ b/validators/display-value.schema.js
@@ -11,5 +11,5 @@ export const displayValueSchema = object({
 
 export const removeDisplayValueSchema = displayValueSchema.pick(['id']);
 
-// TODO: On creating "reg_format" can be BOOL if "reg_type" is "DI" or "DO"
+// TODO: "reg_format" can be BOOL if "reg_type" is "DI" or "DO"
 export const createDisplayValueSchema = displayValueSchema.omit(['id'])
\ No newline at end of file
diff --git a/validators/index.js b/validators/index.js
index 4cb17c4..8ca36e9 100644
--- a/validators/index.js
+++ b/validators/index.js
@@ -14,7 +14,7 @@ export const appConfigSchema = object({
   mb_rtu_parity: string().oneOf(["none", "even", "odd"]).when("mb_connection_type", requiredIfConnTypeEquals("RTU")),
   mb_rtu_data_bits: number().oneOf([7, 8, 9]).when("mb_connection_type", requiredIfConnTypeEquals("RTU")),
   mb_rtu_stop_bits: number().oneOf([1, 2]).when("mb_connection_type", requiredIfConnTypeEquals("RTU")),
-  log_interval_ms: number().min(1000).required(),
+  log_interval_ms: number().min(500).max(10000).required(),
 });
 
 export * from './modbus-device.schema.js'
diff --git a/validators/modbus-device.schema.js b/validators/modbus-device.schema.js
index e5a892d..0b4ce2e 100644
--- a/validators/modbus-device.schema.js
+++ b/validators/modbus-device.schema.js
@@ -9,4 +9,7 @@ export const modbusDeviceSchema = object({
   g_y_label: string().max(40).nullable(),
 });
 
-export const removeModbusDeviceSchema = modbusDeviceSchema.pick(['id']);
\ No newline at end of file
+export const removeModbusDeviceSchema = modbusDeviceSchema.pick(['id']);
+export const editModbusDeviceSchema = modbusDeviceSchema.shape({
+  newId: number().required()
+})
\ No newline at end of file