From d6f7444266661aa565cfab5fdeaa2f08841a7607 Mon Sep 17 00:00:00 2001
From: sergeyyarkov <serzh.yarkov@gmail.com>
Date: Thu, 2 Nov 2023 21:46:50 +0300
Subject: [PATCH] refactor

---
 controllers/modbus.controller.js |  56 +++++++------
 data.db                          | Bin 20480 -> 20480 bytes
 public/css/dist.css              |  35 ++------
 public/index.html                | 137 +++++++++++++++++++++++++------
 public/js/app.js                 |  29 +++----
 services/modbus.service.js       | 135 ++++++++++++++----------------
 6 files changed, 231 insertions(+), 161 deletions(-)

diff --git a/controllers/modbus.controller.js b/controllers/modbus.controller.js
index c0bfb87..7d69ae0 100644
--- a/controllers/modbus.controller.js
+++ b/controllers/modbus.controller.js
@@ -13,7 +13,7 @@ export const modbusController = {
     try {
       const appConfig = await appService.getConfig();
       if (!appConfig) return res.status(400).json({ message: "Application is not configured" });
-      await modbusService.connect(appConfig)
+      await modbusService.connect(appConfig);
       return res.status(200).json({ message: "Connected." });
     } catch (error) {
       next(error);
@@ -60,7 +60,8 @@ export const modbusController = {
    */
   async createDevice(req, res, next) {
     try {
-      const { id, name, g_display_reg_addr, g_display_reg_format, g_display_reg_type, g_y_label, is_logging } = req.body;
+      const { id, name, g_display_reg_addr, g_display_reg_format, g_display_reg_type, g_y_label, is_logging } =
+        req.body;
       await db.run(
         `INSERT INTO "modbus_slaves" (
                     "id", 
@@ -168,37 +169,46 @@ export const modbusController = {
    */
   async streamData(req, res, next) {
     try {
-      if (!modbusClient.isOpen) return res.status(503).json({ error: { message: "Modbus connection closed." } });
-      
       const { slave_id } = req.query;
-      
-      if (!slave_id) 
-        return res.status(400).json({ error: { message: "'slave_id' parameter is required." } });
-      
-      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." } });
 
-      // modbusService.createPollInterval(req, res, device).poll(1000);
+      if (!modbusClient.isOpen) return res.status(503).json({ error: { message: "Modbus connection closed." } });
+      if (!slave_id) return res.status(400).json({ error: { message: "'slave_id' parameter is required." } });
+
+      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");
 
-      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);
+      const intervalId = modbusService.startDevicePollInterval(
+        device,
+        (data, error) => {
+          if (error) {
+            next(error);
+            return;
+          }
           res.write("event: message\n");
           res.write(`data: ${JSON.stringify(data)}\n\n`);
-        } catch (error) {
-          clearInterval(streamInterval);
-          next(error);
-        }
-      }, 1000);
+        },
+        1000,
+      );
 
-      req.on("close", () => clearInterval(streamInterval));
+      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: ${JSON.stringify(data)}\n\n`);
+      //   } catch (error) {
+      //     clearInterval(streamInterval);
+      //     next(error);
+      //   }
+      // }, 1000);
+
+      // req.on("close", () => clearInterval(streamInterval));
     } catch (error) {
       next(error);
     }
diff --git a/data.db b/data.db
index 2b1489b6dca84ce72b984f63209d2c44a7dbd800..4b0af30dc8b13cb45d3c805575068659ca8c77c1 100644
GIT binary patch
delta 114
zcmZozz}T>Wae}nqRt5$JRv?A~MyZK9#*AAxCfsLdWZCS%;mN|tyt#{~N|=q2{{{p9
zjm?4vC-^4@uxY3<a5D(2Gx0KsGIBD7I0qP78tECDS?C$)85$Tfep7A8%g;;YV1BVl
Mfkj|5i^Cs&0E<BydjJ3c

delta 111
zcmZozz}T>Wae}nq0tN;KRv?A~Mv;j+#*7O#CfsLdWZvw+;mN|tvbl?=N_a7gfdCsL
z|4jz|o0|m{j`L3p;80g(;ARk(XA))-W#nWEaSkvvGS@QzLPN%H#VN(A4SD%_sT|BN
I7C8t205lsJp#T5?

diff --git a/public/css/dist.css b/public/css/dist.css
index d242996..cd4f58e 100644
--- a/public/css/dist.css
+++ b/public/css/dist.css
@@ -766,18 +766,10 @@ video {
   min-width: 256px;
 }
 
-.max-w-2xl {
-  max-width: 42rem;
-}
-
 .max-w-5xl {
   max-width: 64rem;
 }
 
-.max-w-xl {
-  max-width: 36rem;
-}
-
 .max-w-md {
   max-width: 28rem;
 }
@@ -854,6 +846,10 @@ video {
   justify-content: space-between;
 }
 
+.justify-evenly {
+  justify-content: space-evenly;
+}
+
 .gap-2 {
   gap: 0.5rem;
 }
@@ -956,6 +952,10 @@ video {
   padding: 10rem;
 }
 
+.p-5 {
+  padding: 1.25rem;
+}
+
 .p-60 {
   padding: 15rem;
 }
@@ -964,10 +964,6 @@ video {
   padding: 20rem;
 }
 
-.p-5 {
-  padding: 1.25rem;
-}
-
 .px-2 {
   padding-left: 0.5rem;
   padding-right: 0.5rem;
@@ -983,21 +979,6 @@ video {
   padding-bottom: 0.75rem;
 }
 
-.px-6 {
-  padding-left: 1.5rem;
-  padding-right: 1.5rem;
-}
-
-.py-4 {
-  padding-top: 1rem;
-  padding-bottom: 1rem;
-}
-
-.px-5 {
-  padding-left: 1.25rem;
-  padding-right: 1.25rem;
-}
-
 .pl-0 {
   padding-left: 0px;
 }
diff --git a/public/index.html b/public/index.html
index d9b2150..cd81eac 100644
--- a/public/index.html
+++ b/public/index.html
@@ -28,12 +28,16 @@
                 <span x-show="devices.length === 0" class="text-gray-500 text-sm text-center block">
                   No devices added.
                 </span>
-                <div @add-device.window="devices = [...devices, $event.detail];" class="flex flex-col max-h-[400px] overflow-y-auto space-y-2">
+                <div
+                  @add-device.window="devices = [...devices, $event.detail];"
+                  class="flex flex-col max-h-[400px] overflow-y-auto space-y-2"
+                >
                   <template x-for="device in devices" :key="device.id">
                     <button
                       @click="selectDevice(device)"
                       :class="{'bg-gray-100': selectedDevice?.id === device.id}"
-                      class="w-full min-h-[50px] select-none border px-2.5 py-3 text-left rounded-sm hover:bg-gray-100 cursor-pointer">
+                      class="w-full min-h-[50px] select-none border px-2.5 py-3 text-left rounded-sm hover:bg-gray-100 cursor-pointer"
+                    >
                       <span x-text="device.name" class="text-md font-bold"></span>
                     </button>
                   </template>
@@ -45,7 +49,8 @@
                     @open-create-device-modal.window="open()"
                     @keyup.escape.window="close()"
                     class="backdrop z-50"
-                    x-show="isOpen">
+                    x-show="isOpen"
+                  >
                     <div class="modal">
                       <div class="flex justify-between items-center">
                         <h2 class="font-bold text-lg">Create new device</h2>
@@ -60,14 +65,33 @@
                       </div>
                       <hr />
                       <form @submit.prevent="create(() => graphView = 'none')" action="#">
-                        <div x-id="['id', 'name', 'graph-display', 'g_display_reg_addr', 'g_display_reg_format', 'g_y_label', 'is_logging']" class="flex flex-col space-y-2">
+                        <div
+                          x-id="['id', 'name', 'graph-display', 'g_display_reg_addr', 'g_display_reg_format', 'g_y_label', 'is_logging']"
+                          class="flex flex-col space-y-2"
+                        >
                           <div>
                             <label :for="$id('id')"><span class="text-red-500">*</span>Slave ID:</label>
-                            <input x-model.number="data.id" :id="$id('id')" name="id" placeholder="1" type="number" min="1" max="255" required />
+                            <input
+                              x-model.number="data.id"
+                              :id="$id('id')"
+                              name="id"
+                              placeholder="1"
+                              type="number"
+                              min="1"
+                              max="255"
+                              required
+                            />
                           </div>
                           <div>
                             <label :for="$id('name')"><span class="text-red-500">*</span>Name:</label>
-                            <input x-model="data.name" placeholder="Device #1" :id="$id('name')" name="name" type="text" required />
+                            <input
+                              x-model="data.name"
+                              placeholder="Device #1"
+                              :id="$id('name')"
+                              name="name"
+                              type="text"
+                              required
+                            />
                           </div>
                           <div>
                             <label :for="$id('graph-display')">Graph Display</label>
@@ -79,22 +103,54 @@
                           <div x-show="graphView === 'new-value'">
                             <div>
                               <label :for="$id('g_y_label')"><span class="text-red-500">*</span>Value name:</label>
-                              <input x-model="data.g_y_label" :id="$id('g_y_label')" :required="graphView === 'new-value'" name="g_y_label" placeholder="PV" type="text" />
+                              <input
+                                x-model="data.g_y_label"
+                                :id="$id('g_y_label')"
+                                :required="graphView === 'new-value'"
+                                name="g_y_label"
+                                placeholder="PV"
+                                type="text"
+                              />
                             </div>
                             <div>
-                              <label :for="$id('g_display_reg_addr')"><span class="text-red-500">*</span>Register address:</label>
-                              <input x-model="data.g_display_reg_addr" :id="$id('g_display_reg_addr')" name="g_display_reg_addr" placeholder="1" type="number" min="0" max="65534" :required="graphView === 'new-value'" />
+                              <label :for="$id('g_display_reg_addr')"
+                                ><span class="text-red-500">*</span>Register address:</label
+                              >
+                              <input
+                                x-model="data.g_display_reg_addr"
+                                :id="$id('g_display_reg_addr')"
+                                name="g_display_reg_addr"
+                                placeholder="1"
+                                type="number"
+                                min="0"
+                                max="65534"
+                                :required="graphView === 'new-value'"
+                              />
                             </div>
                             <div>
-                              <label :for="$id('g_display_reg_type')"><span class="text-red-500">*</span>Registers type:</label>
-                              <select x-model="data.g_display_reg_type" :id="$id('g_display_reg_type')" name="g_display_reg_type" :required="graphView === 'new-value'">
+                              <label :for="$id('g_display_reg_type')"
+                                ><span class="text-red-500">*</span>Registers type:</label
+                              >
+                              <select
+                                x-model="data.g_display_reg_type"
+                                :id="$id('g_display_reg_type')"
+                                name="g_display_reg_type"
+                                :required="graphView === 'new-value'"
+                              >
                                 <option value="IR">Input Registers</option>
                                 <option value="HR">Holding Registers</option>
                               </select>
                             </div>
                             <div>
-                              <label :for="$id('g_display_reg_format')"><span class="text-red-500">*</span>Format (type):</label>
-                              <select x-model="data.g_display_reg_format" :id="$id('g_display_reg_format')" name="g_display_reg_format" :required="graphView === 'new-value'">
+                              <label :for="$id('g_display_reg_format')"
+                                ><span class="text-red-500">*</span>Format (type):</label
+                              >
+                              <select
+                                x-model="data.g_display_reg_format"
+                                :id="$id('g_display_reg_format')"
+                                name="g_display_reg_format"
+                                :required="graphView === 'new-value'"
+                              >
                                 <option value="UI16">Unsigned Int 16</option>
                                 <option value="I16">Signed Int 16</option>
                                 <option value="UI32">Unsigned Int 32</option>
@@ -103,7 +159,12 @@
                               </select>
                             </div>
                             <div>
-                              <input x-model="data.is_logging" :id="$id('is_logging')" name="is_logging" type="checkbox" />
+                              <input
+                                x-model="data.is_logging"
+                                :id="$id('is_logging')"
+                                name="is_logging"
+                                type="checkbox"
+                              />
                               <label :for="$id('is_logging')">Logging</label>
                             </div>
                           </div>
@@ -112,7 +173,14 @@
                           <span x-text="error?.message" class="text-red-500"></span>
                         </div>
                         <div class="mt-4 flex justify-end space-x-2">
-                          <button x-bind:disabled="isLoading" x-bind:class="isLoading && 'opacity-70'" type="submit" class="btn">Create</button>
+                          <button
+                            x-bind:disabled="isLoading"
+                            x-bind:class="isLoading && 'opacity-70'"
+                            type="submit"
+                            class="btn"
+                          >
+                            Create
+                          </button>
                           <button @click="close()" class="btn bg-red-500">Cancel</button>
                         </div>
                       </form>
@@ -122,7 +190,8 @@
                 <!-- Create new device -->
                 <button
                   @click="$dispatch('open-create-device-modal')"
-                  class="w-full min-h-[50px] text-center border-2 border-dashed rounded-sm hover:bg-gray-50 cursor-pointer">
+                  class="w-full min-h-[50px] text-center border-2 border-dashed rounded-sm hover:bg-gray-50 cursor-pointer"
+                >
                   <span class="text-4xl text-gray-400 select-none">+</span>
                 </button>
               </div>
@@ -150,14 +219,16 @@
                   <!-- Device create, delete buttons -->
                   <div>
                     <a href="#">Edit</a>
-                    <a @click="$dispatch('dialog', { 
+                    <a
+                      @click="$dispatch('dialog', { 
                                           title: 'Remove device', 
                                           body: `Remove ${selectedDevice.name}? All logs will be cleared.`,
                                           isOpen: true,
                                           onConfirm: async () => await removeDevice(selectedDevice.id)
                                         });"
                       class="text-red-500"
-                      href="#">
+                      href="#"
+                    >
                       Delete
                     </a>
                   </div>
@@ -169,10 +240,19 @@
                 <!-- Display Graph -->
                 <div x-show="!isLoading && selectedDevice?.g_display_reg_addr !== null" class="mt-4">
                   <div id="div_g" style="width: 720px; height: 300px"></div>
-                  <div class="flex space-x-2 mt-2">
-                    <span class="italic text-sm">Register: <span x-text="selectedDevice?.g_display_reg_addr"></span>&comma;</span>
-                    <span class="italic text-sm">Format: <span x-text="selectedDevice?.g_display_reg_format"></span>&comma;</span>
-                    <span class="italic text-sm">Register type: <span x-text="selectedDevice?.g_display_reg_type"></span></span>
+                  <div class="flex justify-evenly space-x-2 mt-3">
+                    <span class="italic text-sm"
+                      >Value: <span class="font-bold" x-text="selectedDevice?.g_value"></span
+                    ></span>
+                    <span class="italic text-sm">
+                      Register: <span x-text="selectedDevice?.g_display_reg_addr"></span
+                    ></span>
+                    <span class="italic text-sm"
+                      >Format: <span x-text="selectedDevice?.g_display_reg_format"></span
+                    ></span>
+                    <span class="italic text-sm"
+                      >Register type: <span x-text="selectedDevice?.g_display_reg_type"></span
+                    ></span>
                   </div>
                   <hr class="my-3" />
                 </div>
@@ -219,12 +299,14 @@
                                 </svg>
                               </button>
                               <!-- Remove display value -->
-                              <button @click="$dispatch('dialog', { 
+                              <button
+                                @click="$dispatch('dialog', { 
                                 title: 'Remove display value', 
                                 body: `Remove display value ${value.name}?`,
                                 isOpen: true,
                                 onConfirm: async () => await removeDisplayValue(value.id)
-                              });">
+                              });"
+                              >
                                 <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" viewBox="0 0 24 24">
                                   <path
                                     fill="#ef4444"
@@ -236,7 +318,12 @@
                           </div>
                           <hr />
                           <div class="flex flex-col">
-                            <span>Value: <span x-text="value?.data"></span></span>
+                            <span
+                              >Value:
+                              <span
+                                x-text="Number.isInteger(value?.data) ? value?.data : value?.data?.toFixed(3)"
+                              ></span
+                            ></span>
                             <span>Reg Addr: <span x-text="value?.reg_addr"></span></span>
                             <span>Reg Type: <span x-text="value?.reg_type"></span></span>
                             <span>Format: <span x-text="value?.reg_format"></span></span>
diff --git a/public/js/app.js b/public/js/app.js
index c98f0c5..fa48c6e 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -62,13 +62,13 @@ document.addEventListener("alpine:init", async () => {
     isOpen: false,
     isLoading: false,
     error: null,
-    graphView: '',
+    graphView: "",
     data: {
       id: null,
       name: "",
       g_display_reg_addr: null,
       g_display_reg_format: "UI16",
-      g_display_reg_type: 'IR',
+      g_display_reg_type: "IR",
       g_y_label: "",
       is_logging: false,
     },
@@ -77,7 +77,7 @@ document.addEventListener("alpine:init", async () => {
       this.data.name = "";
       this.data.g_display_reg_addr = null;
       this.data.g_display_reg_format = "UI16";
-      this.g_display_reg_type = 'IR';
+      this.g_display_reg_type = "IR";
       this.data.g_y_label = "";
       this.data.is_logging = false;
     },
@@ -103,7 +103,7 @@ document.addEventListener("alpine:init", async () => {
     close() {
       this.isOpen = false;
       this.resetDataFields();
-      this.graphView = '';
+      this.graphView = "";
     },
   }));
 
@@ -130,26 +130,27 @@ document.addEventListener("alpine:init", async () => {
       }
     },
     selectDevice(device) {
-      if (device.id === this.selectedDevice?.id)  return;
-      
+      if (device.id === this.selectedDevice?.id) return;
+
       this.error = null;
       this.selectedDevice = device;
       this.resetGraph();
-      
-      // if (device.g_display_reg_addr !== null) 
-        this.isLoading = true;
-      
+
+      // if (device.g_display_reg_addr !== null)
+      this.isLoading = true;
+
       dataStreamSource?.close();
       dataStreamSource = new EventSource(`/api/modbus/data_stream?slave_id=${device.id}`);
       dataStreamSource.onerror = (e) => {
         dataStreamSource.close();
         this.isLoading = false;
-        this.error = { message: 'Something went wrong.' }
-      }
+        this.error = { message: "Something went wrong." };
+      };
       dataStreamSource.onmessage = (e) => {
         const data = JSON.parse(e.data);
-        console.log('[SSE Message]', data);
+        console.log("[SSE Message]", data);
         if (data.graph !== null) {
+          this.selectedDevice.g_value = data.graph.value;
           graphData.push([new Date(), data.graph.value]);
           if (g === null) {
             g = new Dygraph(document.getElementById("div_g"), graphData, {
@@ -161,7 +162,7 @@ document.addEventListener("alpine:init", async () => {
           }
           g.updateOptions({ file: graphData });
         }
-        data.displayValues.forEach((v, i) => this.selectedDevice.display_values[i] = v);
+        data.displayValues.forEach((v, i) => (this.selectedDevice.display_values[i] = v));
         this.isLoading = false;
       };
     },
diff --git a/services/modbus.service.js b/services/modbus.service.js
index d4f3009..0799227 100644
--- a/services/modbus.service.js
+++ b/services/modbus.service.js
@@ -1,6 +1,6 @@
 import modbusClient from "#root/config/modbus-client.config.js";
 import db from "#root/config/database.config.js";
-import * as utils from '#root/utils/index.js'
+import * as utils from "#root/utils/index.js";
 
 export const modbusService = {
   /**
@@ -9,26 +9,30 @@ export const modbusService = {
    */
   async readDataFromDevice(device) {
     const { g_display_reg_format, g_display_reg_addr, g_display_reg_type, display_values } = device;
-    
+
     /** @type {import("..").EventDataStream} */
     const data = { graph: null, displayValues: [] };
 
     modbusClient.setID(device.id);
-    
+
     /* Read data for graph */
     if (g_display_reg_addr !== null) {
-      const graphValueBuf = await this.readModbusRegisters(g_display_reg_addr, g_display_reg_type, g_display_reg_format);
+      const graphValueBuf = await this.readModbusRegisters(
+        g_display_reg_addr,
+        g_display_reg_type,
+        g_display_reg_format,
+      );
       data.graph = {
-        value: utils.readNumberFromBuf(graphValueBuf, device.g_display_reg_format, 'BE'),
-        format: g_display_reg_format
-      }
+        value: utils.readNumberFromBuf(graphValueBuf, device.g_display_reg_format, "BE"),
+        format: g_display_reg_format,
+      };
     }
 
     /* Read data for display values */
     if (display_values) {
       for (const v of device.display_values) {
-        const displayValueBuf = await this.readModbusRegisters(v.reg_addr, v.reg_type, v.reg_format)
-        v.data = utils.readNumberFromBuf(displayValueBuf, v.reg_format, 'BE')
+        const displayValueBuf = await this.readModbusRegisters(v.reg_addr, v.reg_type, v.reg_format);
+        v.data = utils.readNumberFromBuf(displayValueBuf, v.reg_format, "BE");
         data.displayValues.push(v);
       }
     }
@@ -41,16 +45,16 @@ export const modbusService = {
    * @return {Promise<void>}
    */
   async connect(appConfig) {
-    const { 
-            mb_connection_type, 
-            mb_tcp_ip, 
-            mb_tcp_port,
-            mb_rtu_path,
-            mb_rtu_baud,
-            mb_rtu_data_bits,
-            mb_rtu_parity,
-            mb_rtu_stop_bits 
-          } = appConfig
+    const {
+      mb_connection_type,
+      mb_tcp_ip,
+      mb_tcp_port,
+      mb_rtu_path,
+      mb_rtu_baud,
+      mb_rtu_data_bits,
+      mb_rtu_parity,
+      mb_rtu_stop_bits,
+    } = appConfig;
 
     if (modbusClient.isOpen) {
       modbusClient.close(undefined);
@@ -58,23 +62,21 @@ export const modbusService = {
     }
 
     switch (mb_connection_type) {
-      case 'TCP':
-        {
-          await modbusClient.connectTCP(mb_tcp_ip, { port: mb_tcp_port });
-          break;
-        }
-      case "RTU":
-        {
-          await modbusClient.connectRTU(mb_rtu_path, {
-            baudRate: mb_rtu_baud,
-            dataBits: mb_rtu_data_bits,
-            parity: mb_rtu_parity,
-            stopBits: mb_rtu_stop_bits,
-          });
-          break;
-        }
+      case "TCP": {
+        await modbusClient.connectTCP(mb_tcp_ip, { port: mb_tcp_port });
+        break;
+      }
+      case "RTU": {
+        await modbusClient.connectRTU(mb_rtu_path, {
+          baudRate: mb_rtu_baud,
+          dataBits: mb_rtu_data_bits,
+          parity: mb_rtu_parity,
+          stopBits: mb_rtu_stop_bits,
+        });
+        break;
+      }
       default:
-        throw new Error('Unsupported connection type!')
+        throw new Error("Unsupported connection type!");
     }
   },
 
@@ -89,29 +91,29 @@ export const modbusService = {
     let len = 1;
 
     switch (format) {
-      case 'UI32':
-      case 'I32':
-      case 'FP32':
+      case "UI32":
+      case "I32":
+      case "FP32":
         len = 2;
         break;
       default:
         break;
     }
-  
+
     switch (type) {
-      case 'HR':
-        data = await modbusClient.readHoldingRegisters(addr, len);  
+      case "HR":
+        data = await modbusClient.readHoldingRegisters(addr, len);
         break;
-      case 'IR':
+      case "IR":
         data = await modbusClient.readInputRegisters(addr, len);
         break;
-      case 'DI':
+      case "DI":
         data = await modbusClient.readDiscreteInputs(addr, len);
         break;
       default:
-        throw new Error('Incorrect modbus register type!');
+        throw new Error("Incorrect modbus register type!");
     }
-  
+
     return data.buffer;
   },
 
@@ -136,35 +138,24 @@ export const modbusService = {
     `);
     // @ts-ignore
     devices.forEach((s) => (s.display_values = JSON.parse(s.display_values)));
-    return devices
+    return devices;
   },
 
   /**
-   * @param {import('express').Request} req
-   * @param {import('express').Response} res 
    * @param {import("..").ModbusDevice} device
+   * @param {(data: import("..").EventDataStream, error: any) => void} callback
+   * @param {number} intervalMs
    */
-  // createPollInterval(req, res, device, pollIntervalMs) {
-  //   let intervalId;
-
-  //   res.setHeader("Cache-Control", "no-cache");
-  //   res.setHeader("Content-Type", "text/event-stream");
-  //   res.setHeader("Connection", "keep-alive");
-
-  //   return {
-  //     /**
-  //      * @param {number} pollIntervalMs
-  //      */
-  //     poll(pollIntervalMs) {
-  //       intervalId = setInterval(async () => {
-  //         device.display_values = await db.all(`SELECT * FROM "display_values" WHERE slave_id = ?`, [device.id]) 
-  //         const data = await modbusService.readDataFromDevice(device);
-  //         res.write("event: message\n");
-  //         res.wriste(`data: ${JSON.stringify(data)}\n\n`);
-  //       }, pollIntervalMs)
-
-  //       req.on("close", () => clearInterval(intervalId));
-  //     }
-  //   }
-  // }
-}
\ No newline at end of file
+  startDevicePollInterval(device, callback, intervalMs) {
+    const poll = async () => {
+      try {
+        device.display_values = await db.all(`SELECT * FROM "display_values" WHERE slave_id = ?`, [device.id]);
+        const data = await this.readDataFromDevice(device);
+        callback(data);
+      } catch (error) {
+        callback(null, error);
+      }
+    };
+    return setInterval(poll, intervalMs);
+  },
+};