diff --git a/test_apps/broadcast_test/CMakeLists.txt b/test_apps/broadcast_test/CMakeLists.txt
new file mode 100644
index 0000000..266331d
--- /dev/null
+++ b/test_apps/broadcast_test/CMakeLists.txt
@@ -0,0 +1,15 @@
+# This is the project CMakeLists.txt file for the test subproject
+cmake_minimum_required(VERSION 3.22)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+set(EXTRA_COMPONENT_DIRS "../test_common")
+
+# The workaround for the test_utils under ESP-IDF v6.0
+if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER "5.5")
+    list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/tools/test_apps/components")
+else()
+    list(APPEND EXTRA_COMPONENT_DIRS "$ENV{IDF_PATH}/tools/unit-test-app/components")
+endif()
+
+project(test_broadcast)
diff --git a/test_apps/broadcast_test/README.md b/test_apps/broadcast_test/README.md
new file mode 100644
index 0000000..28ab9f5
--- /dev/null
+++ b/test_apps/broadcast_test/README.md
@@ -0,0 +1,4 @@
+| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-H2 | ESP32-S2 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | -------- | -------- |
+
+This test app is used to test modbus interface feature.
diff --git a/test_apps/broadcast_test/main/CMakeLists.txt b/test_apps/broadcast_test/main/CMakeLists.txt
new file mode 100644
index 0000000..d0dc01a
--- /dev/null
+++ b/test_apps/broadcast_test/main/CMakeLists.txt
@@ -0,0 +1,18 @@
+set(PROJECT "test_bcast")
+
+set(srcs "test_app_main.c"
+            "${PROJECT}_serial.c"
+)
+
+idf_component_register(SRCS ${srcs}
+                        PRIV_REQUIRES test_utils test_common unity
+                        )
+
+# The workaround for WHOLE_ARCHIVE which is absent in v4.4
+set_property(TARGET ${COMPONENT_LIB} APPEND PROPERTY INTERFACE_LINK_LIBRARIES "-u mb_test_include_bcast_serial")
+
+# Workaround to avoid static analysis false positives for some components.
+if(CONFIG_FMB_COMPILER_STATIC_ANALYZER_ENABLE AND CMAKE_C_COMPILER_ID STREQUAL "GNU")
+    target_compile_options(${COMPONENT_LIB} PRIVATE "-fanalyzer")
+    message(STATUS "Static analyzer build for ${PROJECT_NAME}.")
+endif()
diff --git a/test_apps/broadcast_test/main/Kconfig.projbuild b/test_apps/broadcast_test/main/Kconfig.projbuild
new file mode 100644
index 0000000..b56bf41
--- /dev/null
+++ b/test_apps/broadcast_test/main/Kconfig.projbuild
@@ -0,0 +1,45 @@
+menu "Modbus Test Configuration"
+
+    config MB_PORT_ADAPTER_EN
+        bool "Enable Modbus port adapter to substitute hardware layer for test."
+        default n
+        help
+            When option is enabled the port communication layer is substituted by
+            port adapter layer to allow testing of higher layers without access to physical layer.
+
+    config MB_TEST_SLAVE_TASK_PRIO
+        int "Modbus master test task priority"
+        range 4 23
+        default 4
+        help
+            Modbus master task priority for the test.
+
+    config MB_TEST_MASTER_TASK_PRIO
+        int "Modbus slave test task priority"
+        range 4 23
+        default 4
+        help
+            Modbus slave task priority for the test.
+
+    config MB_TEST_COMM_CYCLE_COUNTER
+        int "Modbus test communication cycle counter"
+        range 10 1000
+        default 10
+        help
+            Modbus communication cycle counter for test.
+
+    config MB_TEST_LEAK_WARN_LEVEL
+        int "Modbus test leak warning level"
+        range 4 256
+        default 32
+        help
+            Modbus test leak warning level.
+
+    config MB_TEST_LEAK_CRITICAL_LEVEL
+        int "Modbus test leak critical level"
+        range 4 1024
+        default 64
+        help
+            Modbus test leak critical level.
+
+endmenu
diff --git a/test_apps/broadcast_test/main/idf_component.yml b/test_apps/broadcast_test/main/idf_component.yml
new file mode 100644
index 0000000..8dee941
--- /dev/null
+++ b/test_apps/broadcast_test/main/idf_component.yml
@@ -0,0 +1,5 @@
+dependencies:
+  idf: ">=5.0"
+  espressif/esp-modbus:
+    version: "^2"
+    override_path: "../../../"
diff --git a/test_apps/broadcast_test/main/test_app_main.c b/test_apps/broadcast_test/main/test_app_main.c
new file mode 100644
index 0000000..ccf63d5
--- /dev/null
+++ b/test_apps/broadcast_test/main/test_app_main.c
@@ -0,0 +1,22 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: CC0-1.0
+ */
+
+#include "unity.h"
+#include "test_common.h"
+
+void app_main(void)
+{
+#if !CONFIG_LOG_DEFAULT_LEVEL_DEBUG
+    esp_log_level_set("mbc_tcp.slave", ESP_LOG_DEBUG);
+    esp_log_level_set("mbc_serial.slave", ESP_LOG_DEBUG);
+    esp_log_level_set("mb_object.slave", ESP_LOG_DEBUG);
+#else
+    // Disable VFS logs as they are too verbose
+    esp_log_level_set("vfs_calls", ESP_LOG_NONE);
+#endif
+    printf("Modbus RS485 multi-device test cases/n");
+    unity_run_menu();
+}
diff --git a/test_apps/broadcast_test/main/test_bcast_serial.c b/test_apps/broadcast_test/main/test_bcast_serial.c
new file mode 100644
index 0000000..1b6efef
--- /dev/null
+++ b/test_apps/broadcast_test/main/test_bcast_serial.c
@@ -0,0 +1,210 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2026 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include "unity.h"
+
+#include "sdkconfig.h"
+#include "test_common.h"
+#include "test_utils.h"
+
+#if __has_include("unity_test_utils.h")
+// unity test utils are used
+#include "unity_test_utils.h"
+#else
+// Unit_test_app utils from test_utils ("test_utils.h"), v4.4
+#define unity_utils_task_delete test_utils_task_delete
+#endif
+
+#define TEST_SER_PORT_NUM               (1)
+#define TEST_TASK_TIMEOUT_MS            (160000)
+#define TEST_SEND_TOUT_US               (30000)
+#define TEST_RESP_TOUT_MS               (1000)
+#define TEST_BAUD_RATE                  (115200)
+
+#if CONFIG_IDF_TARGET_ESP32
+#define TEST_SER_PIN_RX                 (22)
+#define TEST_SER_PIN_TX                 (23)
+// RTS for RS485 Half-Duplex Mode manages DE/~RE
+#define TEST_SER_PIN_RTS                (18)
+#else
+#define TEST_SER_PIN_RX                 (4)
+#define TEST_SER_PIN_TX                 (5)
+#define TEST_SER_PIN_RTS                (10)
+#endif
+
+#define TEST_MASTER_RESPOND_TOUT_MS     (CONFIG_FMB_MASTER_TIMEOUT_MS_RESPOND)
+
+// The workaround to statically link the whole test library
+__attribute__((unused)) bool mb_test_include_bcast_serial = true;
+
+#define TAG "MODBUS_SERIAL_COMM_TEST"
+
+#if (CONFIG_FMB_COMM_MODE_RTU_EN || CONFIG_FMB_COMM_MODE_ASCII_EN)
+
+#define MB_DEVICE_ADDR0 0
+
+// Example Data (Object) Dictionary for Modbus parameters
+static const mb_parameter_descriptor_t descriptors[] = {
+    {
+        CID_DEV_REG0, STR("MB_hold_reg-0"), STR("Data"), MB_DEVICE_ADDR0, MB_PARAM_HOLDING, 0, 1,
+        0, PARAM_TYPE_U16, 2, OPTS(0, 0, 0), PAR_PERMS_READ_WRITE_TRIGGER
+    },
+    {
+        CID_DEV_REG1, STR("MB_hold_reg-1"), STR("Data"), MB_DEVICE_ADDR0, MB_PARAM_HOLDING, 1, 1,
+        0, PARAM_TYPE_U16, 2, OPTS(0, 0, 0), PAR_PERMS_READ_WRITE_TRIGGER
+    },
+    {
+        CID_DEV_REG2, STR("MB_hold_reg-2"), STR("Data"), MB_DEVICE_ADDR0, MB_PARAM_HOLDING, 2, 1,
+        0, PARAM_TYPE_U16, 2, OPTS(0, 0, 0), PAR_PERMS_READ_WRITE_TRIGGER
+    },
+    {
+        CID_DEV_REG3, STR("MB_hold_reg-3"), STR("Data"), MB_DEVICE_ADDR0, MB_PARAM_HOLDING, 3, 1,
+        0, PARAM_TYPE_U16, 2, OPTS(0, 0, 0), PAR_PERMS_READ_WRITE_TRIGGER
+    },
+    {
+        CID_DEV_REG_COUNT, STR("CYCLE_COUNTER"), STR("Data"), MB_DEVICE_ADDR1, MB_PARAM_HOLDING, 4, 1,
+        0, PARAM_TYPE_U16, 2, OPTS(0, 0, 0), PAR_PERMS_READ_WRITE_TRIGGER
+    }
+};
+
+// The number of parameters in the table
+const uint16_t num_descriptors = (sizeof(descriptors) / sizeof(descriptors[0]));
+
+static void test_modbus_rs485_rtu_slave(void)
+{
+    mb_communication_info_t slave_config1 = {
+        .ser_opts.port = TEST_SER_PORT_NUM,
+        .ser_opts.mode = MB_RTU,
+        .ser_opts.uid = MB_DEVICE_ADDR1,
+        .ser_opts.data_bits = UART_DATA_8_BITS,
+        .ser_opts.stop_bits = UART_STOP_BITS_1,
+        .ser_opts.baudrate = TEST_BAUD_RATE,
+        .ser_opts.parity = UART_PARITY_DISABLE,
+        .ser_opts.response_tout_ms = TEST_MASTER_RESPOND_TOUT_MS,
+        .ser_opts.test_tout_us = TEST_SEND_TOUT_US
+    };
+
+    TaskHandle_t slave_task_handle = test_common_slave_serial_create(&slave_config1, 0);
+
+    // Set driver mode to Half Duplex
+    TEST_ESP_OK(uart_set_mode(slave_config1.ser_opts.port, UART_MODE_RS485_HALF_DUPLEX));
+    TEST_ESP_OK(uart_set_pin(slave_config1.ser_opts.port, TEST_SER_PIN_TX,
+                             TEST_SER_PIN_RX, TEST_SER_PIN_RTS, UART_PIN_NO_CHANGE));
+
+    ESP_LOGI(TAG, "Slave RTU is started. (%s).", __func__);
+
+    unity_send_signal("Slave_ready");
+    unity_wait_for_signal("Master_started");
+
+    test_common_task_start(slave_task_handle, 1);
+    TEST_ASSERT_TRUE(test_common_task_wait_done(slave_task_handle, pdMS_TO_TICKS(TEST_TASK_TIMEOUT_MS)));
+}
+
+static void test_modbus_rs485_rtu_master(void)
+{
+    ESP_LOGI(TAG, "Master RTU is started (%s).", __func__);
+    unity_wait_for_signal("Slave_ready");
+    unity_send_signal("Master_started");
+
+    // Initialize and start Modbus controller
+    mb_communication_info_t master_config = {
+        .ser_opts.port = TEST_SER_PORT_NUM,
+        .ser_opts.mode = MB_RTU,
+        .ser_opts.data_bits = UART_DATA_8_BITS,
+        .ser_opts.stop_bits = UART_STOP_BITS_1,
+        .ser_opts.baudrate = TEST_BAUD_RATE,
+        .ser_opts.parity = UART_PARITY_DISABLE,
+        .ser_opts.response_tout_ms = TEST_MASTER_RESPOND_TOUT_MS,
+        .ser_opts.test_tout_us = TEST_SEND_TOUT_US
+    };
+
+    TaskHandle_t master_task_handle = test_common_master_serial_create(&master_config, 0, &descriptors[0], num_descriptors);
+
+    // Set driver mode to Half Duplex
+    TEST_ESP_OK(uart_set_mode(master_config.ser_opts.port, UART_MODE_RS485_HALF_DUPLEX));
+    TEST_ESP_OK(uart_set_pin(master_config.ser_opts.port, TEST_SER_PIN_TX,
+                             TEST_SER_PIN_RX, TEST_SER_PIN_RTS, UART_PIN_NO_CHANGE));
+    void *handle = test_common_task_get_instance(master_task_handle);
+    uint16_t reg = 0;
+    uint8_t type = 0;
+    esp_err_t err = mbc_master_get_parameter(handle, CID_DEV_REG0, (uint8_t *)&reg, &type);
+    TEST_ESP_ERR(ESP_ERR_NOT_SUPPORTED, err); // Broadcast read request is not supported
+    test_common_task_start(master_task_handle, 1);
+
+    TEST_ASSERT_TRUE(test_common_task_wait_done(master_task_handle, pdMS_TO_TICKS(TEST_TASK_TIMEOUT_MS)));
+}
+
+/*
+ * Modbus RS485 RTU multi device test case
+ */
+TEST_CASE_MULTIPLE_DEVICES("Modbus RS485 RTU multi device broadcast case.", "[modbus][test_env=multi_dut_modbus_serial]", test_modbus_rs485_rtu_slave, test_modbus_rs485_rtu_master);
+
+static void test_modbus_rs485_ascii_slave(void)
+{
+    mb_communication_info_t slave_config1 = {
+        .ser_opts.port = TEST_SER_PORT_NUM,
+        .ser_opts.mode = MB_ASCII,
+        .ser_opts.uid = MB_DEVICE_ADDR1,
+        .ser_opts.data_bits = UART_DATA_8_BITS,
+        .ser_opts.stop_bits = UART_STOP_BITS_1,
+        .ser_opts.baudrate = TEST_BAUD_RATE,
+        .ser_opts.parity = UART_PARITY_DISABLE,
+        .ser_opts.response_tout_ms = TEST_MASTER_RESPOND_TOUT_MS,
+        .ser_opts.test_tout_us = TEST_SEND_TOUT_US
+    };
+
+    TaskHandle_t slave_task_handle = test_common_slave_serial_create(&slave_config1, 0);
+
+    TEST_ESP_OK(uart_set_pin(slave_config1.ser_opts.port, TEST_SER_PIN_TX,
+                             TEST_SER_PIN_RX, TEST_SER_PIN_RTS, UART_PIN_NO_CHANGE));
+
+    // Set driver mode to Half Duplex
+    TEST_ESP_OK(uart_set_mode(slave_config1.ser_opts.port, UART_MODE_RS485_HALF_DUPLEX));
+
+    ESP_LOGI(TAG, "Slave ASCII is started. (%s).", __func__);
+
+    unity_send_signal("Slave_ready");
+    unity_wait_for_signal("Master_started");
+
+    test_common_task_start(slave_task_handle, 1);
+    TEST_ASSERT_TRUE(test_common_task_wait_done(slave_task_handle, pdMS_TO_TICKS(TEST_TASK_TIMEOUT_MS)));
+};
+
+static void test_modbus_rs485_ascii_master(void)
+{
+    ESP_LOGI(TAG, "Master ASCII is started (%s).", __func__);
+    unity_wait_for_signal("Slave_ready");
+
+    // Initialize and start Modbus controller
+    mb_communication_info_t master_config = {
+        .ser_opts.port = TEST_SER_PORT_NUM,
+        .ser_opts.mode = MB_ASCII,
+        .ser_opts.data_bits = UART_DATA_8_BITS,
+        .ser_opts.stop_bits = UART_STOP_BITS_1,
+        .ser_opts.baudrate = TEST_BAUD_RATE,
+        .ser_opts.parity = UART_PARITY_DISABLE,
+        .ser_opts.response_tout_ms = TEST_MASTER_RESPOND_TOUT_MS,
+        .ser_opts.test_tout_us = TEST_SEND_TOUT_US
+    };
+
+    TaskHandle_t master_task_handle = test_common_master_serial_create(&master_config, 0, &descriptors[0], num_descriptors);
+
+    // Set driver mode to Half Duplex
+    TEST_ESP_OK(uart_set_mode(master_config.ser_opts.port, UART_MODE_RS485_HALF_DUPLEX));
+    TEST_ESP_OK(uart_set_pin(master_config.ser_opts.port, TEST_SER_PIN_TX,
+                             TEST_SER_PIN_RX, TEST_SER_PIN_RTS, UART_PIN_NO_CHANGE));
+    unity_send_signal("Master_started");
+
+    test_common_task_start(master_task_handle, 1);
+    TEST_ASSERT_TRUE(test_common_task_wait_done(master_task_handle, pdMS_TO_TICKS(TEST_TASK_TIMEOUT_MS)));
+}
+
+/*
+ * Modbus RS485 ASCII multi device test case
+ */
+TEST_CASE_MULTIPLE_DEVICES("Modbus RS485 ASCII multi device broadcast case.", "[modbus][test_env=multi_dut_modbus_serial]", test_modbus_rs485_ascii_slave, test_modbus_rs485_ascii_master);
+
+
+#endif
diff --git a/test_apps/broadcast_test/pytest_bcast_comm.py b/test_apps/broadcast_test/pytest_bcast_comm.py
new file mode 100644
index 0000000..cf06207
--- /dev/null
+++ b/test_apps/broadcast_test/pytest_bcast_comm.py
@@ -0,0 +1,17 @@
+# SPDX-FileCopyrightText: 2022-2026 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: CC0-1.0
+
+import pytest
+
+
+@pytest.mark.parametrize("target", ["esp32"], indirect=True)
+@pytest.mark.parametrize("count, config", [(2, "serial")], indirect=True)
+@pytest.mark.multi_dut_modbus_serial
+def test_modbus_comm_bcast_serial(case_tester) -> None:  # type: ignore
+    for case in case_tester.test_menu:
+        if (
+            case.attributes.get("test_env", "multi_dut_modbus_serial")
+            == "multi_dut_modbus_serial"
+        ):
+            print(f"Test case: {case.name}")
+            case_tester.run_multi_dev_case(case=case, reset=True)
diff --git a/test_apps/broadcast_test/sdkconfig.ci.defaults b/test_apps/broadcast_test/sdkconfig.ci.defaults
new file mode 100644
index 0000000..383ed73
--- /dev/null
+++ b/test_apps/broadcast_test/sdkconfig.ci.defaults
@@ -0,0 +1,25 @@
+#
+# Default configuration options
+#
+CONFIG_FMB_TIMER_USE_ISR_DISPATCH_METHOD=y
+CONFIG_FMB_MASTER_DELAY_MS_CONVERT=300
+CONFIG_FMB_MASTER_TIMEOUT_MS_RESPOND=2000
+CONFIG_FMB_PORT_TASK_STACK_SIZE=4096
+CONFIG_FMB_PORT_TASK_PRIO=10
+
+# Avoid CI issues "Warning: The smallest app partition is nearly full (5% free space left)!"
+CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
+CONFIG_PARTITION_TABLE_SINGLE_APP_LARGE=y
+
+CONFIG_MB_PORT_ADAPTER_EN=n
+CONFIG_MB_TEST_SLAVE_TASK_PRIO=5
+CONFIG_MB_TEST_MASTER_TASK_PRIO=5
+CONFIG_MB_TEST_COMM_CYCLE_COUNTER=30
+
+CONFIG_ESP_TASK_WDT_EN=n
+CONFIG_ESP_TASK_WDT_INIT=n
+
+# Enable debug logging
+CONFIG_LOG_DEFAULT_LEVEL_DEBUG=n
+CONFIG_LOG_MAXIMUM_LEVEL_DEBUG=y
+CONFIG_MB_CONSOLE_HELPER_ENABLED=y
diff --git a/test_apps/broadcast_test/sdkconfig.ci.serial b/test_apps/broadcast_test/sdkconfig.ci.serial
new file mode 100644
index 0000000..e8bdee3
--- /dev/null
+++ b/test_apps/broadcast_test/sdkconfig.ci.serial
@@ -0,0 +1,15 @@
+#
+# Serial-specific configuration
+#
+CONFIG_MB_TEST_SLAVE_TASK_PRIO=5
+CONFIG_MB_TEST_MASTER_TASK_PRIO=5
+
+CONFIG_FMB_COMM_MODE_RTU_EN=y
+CONFIG_FMB_COMM_MODE_ASCII_EN=y
+CONFIG_FMB_COMM_MODE_TCP_EN=n
+CONFIG_FMB_TCP_UID_ENABLED=n
+CONFIG_MB_TEST_COMM_CYCLE_COUNTER=10
+CONFIG_MB_PORT_ADAPTER_EN=n
+CONFIG_MB_TEST_LEAK_CRITICAL_LEVEL=128
+CONFIG_MB_TEST_LEAK_WARN_LEVEL=128
+CONFIG_UNITY_ENABLE_FIXTURE=y
diff --git a/test_apps/test_common/test_common.c b/test_apps/test_common/test_common.c
index 366a741..23d8f68 100644
--- a/test_apps/test_common/test_common.c
+++ b/test_apps/test_common/test_common.c
@@ -7,6 +7,7 @@
 #include "freertos/portmacro.h"
 #include "freertos/queue.h"
 
+#include "esp_modbus_common.h"
 #include "port_adapter.h"
 #include "mb_common.h"
 #include "mbc_slave.h"
@@ -139,6 +140,27 @@ void test_task_add_entry(TaskHandle_t task_handle, void *inst)
     xSemaphoreTake(new_entry->task_sema_handle, 1);
 }
 
+static void *test_task_find_object(bool is_master)
+{
+    task_entry_t *it, *pfound = NULL;
+    if (LIST_EMPTY(&s_task_list)) {
+        return NULL;
+    }
+
+    portENTER_CRITICAL(&s_list_spinlock);
+    LIST_FOREACH(it, &s_task_list, entries) {
+        if (it) {
+            mb_controller_common_t *pobj = (mb_controller_common_t *)it->inst_handle;
+            if (pobj && pobj->mb_base->descr.is_master == is_master) {
+                pfound = (void *)pobj;
+                break;
+            }
+        }
+    }
+    portEXIT_CRITICAL(&s_list_spinlock);
+    return pfound;
+}
+
 static task_entry_t *test_task_find_entry(TaskHandle_t task_handle)
 {
     TEST_ASSERT_NOT_NULL(task_handle);
@@ -438,8 +460,16 @@ esp_err_t test_common_read_modbus_parameter(void *handle, uint16_t cid, uint16_t
         uint8_t type = 0;
         if (param_descriptor->mb_slave_addr) {
             err = mbc_master_get_parameter(handle, cid, (uint8_t *)par_data, &type);
-        } else { // if the address is broadcast, try to read from first slave intentionally
-            err = mbc_master_get_parameter_with(handle, cid, param_descriptor->mb_slave_addr + 1, (uint8_t *)par_data, &type);
+        } else {
+            // if the address is broadcast, try to read from first registered slave intentionally
+            void *pobj = test_task_find_object(false);
+            uint8_t uid = 0x01;
+            if (pobj) {
+                mbs_controller_iface_t *pctrl_obj = ((mbs_controller_iface_t *)pobj);
+                uid = pctrl_obj->opts.comm_opts.common_opts.uid;
+            }
+            ESP_LOGD(TAG, "Use slave object: %p, UID:%u", pobj, uid);
+            err = mbc_master_get_parameter_with(handle, cid, uid, (uint8_t *)par_data, &type);
         }
         if (err == ESP_OK) {
             ESP_LOGI(TAG, "%p, CHAR #%u %s (%s) value = (0x%04x) parameter read successful.",