enable slave ID transfer from master to slave

Author: TomSack

modbus/mb_controller/common/esp_modbus_slave.c

@@ -91,7 +91,7 @@ esp_err_t mbc_slave_delete(void *ctx)
     MB_RETURN_ON_FALSE(ctx, ESP_ERR_INVALID_STATE, TAG,
                         "Slave interface is not correctly initialized.");
     mbs_controller_iface_t *mbs_controller = MB_SLAVE_GET_IFACE(ctx);
-    
+
     // Check if interface has been initialized
     MB_RETURN_ON_FALSE(mbs_controller->delete,
                         ESP_ERR_INVALID_STATE, TAG,
@@ -259,7 +259,7 @@ esp_err_t mbc_slave_set_descriptor(void *ctx, mb_register_area_descriptor_t desc
     } else {
         mb_slave_options_t *mbs_opts = &mbs_controller->opts;
 
-        MB_RETURN_ON_FALSE((descr_data.size < MB_INST_MAX_SIZE) && (descr_data.size >= MB_INST_MIN_SIZE), 
+        MB_RETURN_ON_FALSE((descr_data.size < MB_INST_MAX_SIZE) && (descr_data.size >= MB_INST_MIN_SIZE),
                             ESP_ERR_INVALID_ARG, TAG, "mb area size is incorrect.");
         uint16_t reg_size = REG_SIZE(descr_data.type, descr_data.size);
 
@@ -300,8 +300,14 @@ static esp_err_t mbc_slave_send_param_info(void *ctx, mb_event_group_t par_type,
     MB_RETURN_ON_FALSE(ctx, ESP_ERR_INVALID_STATE, TAG,
                     "Slave interface is not correctly initialized.");
     mb_slave_options_t *mbs_opts = MB_SLAVE_GET_OPTS(ctx);
+    mbs_controller_iface_t *mbs_controller = MB_SLAVE_GET_IFACE(ctx);
     esp_err_t error = ESP_FAIL;
     mb_param_info_t par_info;
+    uint8_t unit_id = MB_TCP_PSEUDO_ADDRESS;
+    if (mbs_controller && mbs_controller->mb_base) {
+        unit_id = mbs_get_request_unit_id(mbs_controller->mb_base);
+    }
+    par_info.unit_id = unit_id;
     // Check if queue is not full the send parameter information
     par_info.type = par_type;
     par_info.size = par_size;

modbus/mb_controller/common/include/esp_modbus_slave.h

@@ -50,6 +50,7 @@ extern "C" {
 typedef struct {
     uint32_t time_stamp;                    /*!< Timestamp of Modbus Event (uS)*/
     uint16_t mb_offset;                     /*!< Modbus register offset */
+    uint8_t unit_id;                        /*!< Unit identifier from the request */
     mb_event_group_t type;                  /*!< Modbus event type */
     uint8_t *address;                       /*!< Modbus data storage address */
     size_t size;                            /*!< Modbus event register size (number of registers)*/
@@ -80,7 +81,7 @@ typedef struct {
  *
  * @param[out] ctx context pointer of the initialized modbus interface
  * @param[in] config - pointer to configuration structure for the slave
- * 
+ *
  * @return
  *     - ESP_OK                 Success
  *     - ESP_ERR_NO_MEM         Parameter error
@@ -94,7 +95,7 @@ esp_err_t mbc_slave_create_tcp(mb_communication_info_t *config, void **ctx);
  *
  * @param[out] ctx context pointer of the initialized modbus interface
  * @param[in] config - pointer to configuration structure for the slave
- * 
+ *
  * @return
  *     - ESP_OK                 Success
  *     - ESP_ERR_NO_MEM         Parameter error
@@ -181,7 +182,7 @@ mb_event_group_t mbc_slave_check_event(void *ctx, mb_event_group_t group);
  * @param[out] reg_info parameter info structure
  * @param[in] timeout Timeout in milliseconds to read information from
  *                    parameter queue
- * 
+ *
  * @return
  *     - ESP_OK Success
  *     - ESP_ERR_TIMEOUT Can not get data from parameter queue

modbus/mb_objects/include/mb_slave.h

@@ -27,6 +27,9 @@ mb_err_enum_t mbs_delete_handler(mb_base_t *inst, uint8_t func_code);
 // The helper function to get count of handlers for slave
 mb_err_enum_t mbs_get_handler_count(mb_base_t *inst, uint16_t *count);
 
+// Get the unit identifier from the currently processed request
+uint8_t mbs_get_request_unit_id(mb_base_t *inst);
+
 #ifdef __cplusplus
 }
-#endif
+#endif

modbus/mb_objects/mb_slave.c

@@ -89,6 +89,13 @@ mb_err_enum_t mbs_get_handler_count(mb_base_t *inst, uint16_t *count)
     return MB_ENOERR;
 }
 
+uint8_t mbs_get_request_unit_id(mb_base_t *inst)
+{
+    MB_RETURN_ON_FALSE(inst, MB_TCP_PSEUDO_ADDRESS, TAG, "slave instance invalid.");
+    mbs_object_t *mbs_obj = MB_GET_OBJ_CTX(inst, mbs_object_t, base);
+    return mbs_obj ? mbs_obj->rcv_addr : MB_TCP_PSEUDO_ADDRESS;
+}
+
 static mb_exception_t mbs_check_invoke_handler(mb_base_t *inst, uint8_t func_code, uint8_t *buf, uint16_t *len)
 {
     mbs_object_t *mbs_obj = MB_GET_OBJ_CTX(inst, mbs_object_t, base);
@@ -201,7 +208,7 @@ mb_err_enum_t mbs_rtu_create(mb_serial_opts_t *ser_opts, void **in_out_obj)
                      TAG, "name alloc fail, err: %d", (int)res);
     transp_obj = (mb_trans_base_t *)mbs_obj;
     ret = mbs_rtu_transp_create(ser_opts, (void **)&transp_obj);
-    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error, 
+    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error,
                                 TAG, "transport creation, err: %d", (int)ret);
     ret = mbs_register_default_handlers(&mbs_obj->base);
     MB_GOTO_ON_FALSE((ret == MB_ENOERR), MB_EILLSTATE, error,
@@ -215,7 +222,7 @@ mb_err_enum_t mbs_rtu_create(mb_serial_opts_t *ser_opts, void **in_out_obj)
     *in_out_obj = (void *)&(mbs_obj->base);
     ESP_LOGD(TAG, "created object %s", mbs_obj->base.descr.parent_name);
     return MB_ENOERR;
-    
+
 error:
     if (transp_obj) {
         mbs_rtu_transp_delete(transp_obj);
@@ -260,7 +267,7 @@ mb_err_enum_t mbs_ascii_create(mb_serial_opts_t *ser_opts, void **in_out_obj)
                      TAG, "name alloc fail, err: %d", (int)res);
     transp_obj = (mb_trans_base_t *)mbs_obj;
     ret = mbs_ascii_transp_create(ser_opts, (void **)&transp_obj);
-    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error, 
+    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error,
                         TAG, "transport creation, err: %d", (int)ret);
     ret = mbs_register_default_handlers(&mbs_obj->base);
     MB_GOTO_ON_FALSE((ret == MB_ENOERR), MB_EILLSTATE, error,
@@ -274,7 +281,7 @@ mb_err_enum_t mbs_ascii_create(mb_serial_opts_t *ser_opts, void **in_out_obj)
     *in_out_obj = (void *)&(mbs_obj->base);
     ESP_LOGD(TAG, "created object %s", mbs_obj->base.descr.parent_name);
     return MB_ENOERR;
-    
+
 error:
     if (transp_obj) {
         mbs_ascii_transp_delete(transp_obj);
@@ -320,7 +327,7 @@ mb_err_enum_t mbs_tcp_create(mb_tcp_opts_t *tcp_opts, void **in_out_obj)
                      TAG, "name alloc fail, err: %d", (int)res);
     transp_obj = (mb_trans_base_t *)mbs_obj;
     ret = mbs_tcp_transp_create(tcp_opts, (void **)&transp_obj);
-    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error, 
+    MB_GOTO_ON_FALSE((transp_obj && (ret == MB_ENOERR)), MB_EILLSTATE, error,
                                 TAG, "transport creation, err: %d", (int)ret);
     ret = mbs_register_default_handlers(&mbs_obj->base);
     MB_GOTO_ON_FALSE((ret == MB_ENOERR), MB_EILLSTATE, error,
@@ -334,7 +341,7 @@ mb_err_enum_t mbs_tcp_create(mb_tcp_opts_t *tcp_opts, void **in_out_obj)
     *in_out_obj = (void *)&(mbs_obj->base);
     ESP_LOGD(TAG, "created object %s", mbs_obj->base.descr.parent_name);
     return MB_ENOERR;
-    
+
 error:
     if (transp_obj) {
         mbs_tcp_transp_delete(transp_obj);
@@ -469,7 +476,7 @@ mb_err_enum_t mbs_poll(mb_base_t *inst)
                 ESP_LOGD(TAG, MB_OBJ_FMT":EV_READY", MB_OBJ_PARENT(inst));
                 mb_port_event_res_release(MB_OBJ(inst->port_obj));
                 break;
-                
+
             case EV_FRAME_RECEIVED:
                 ESP_LOGD(TAG, MB_OBJ_FMT":EV_FRAME_RECEIVED", MB_OBJ_PARENT(inst));
                 mbs_obj->length = event.length;