The present disclosure relates to a communication adapter. More particularly, the present disclosure relates to program update for a communication adapter used in a remote management system for a hot water using facility (such as, for example, a water heater, a multi-water heating system, a reheating system for water in a bath, a filtering apparatus, or a hot water heating apparatus).

BACKGROUND ART

Japanese Patent Laying-Open No. 2017-58026 (PTL 1) describes a remote management system for a multi-water heating system that is one example of a hot water using facility. In the remote management system described in PTL 1, various pieces of information about the water heating system are transmitted to a management center (server) via a communication adapter communicatively connected to the water heating system.

For example, the communication adapter is communicatively connected to the water heating system via a two-wire communication line, and is connected by wireless communication to a router connected to a communication network such as the Internet. Since the communication adapter is communicatively connected to the router and to the management center (server) via the communication network, bidirectional information transmission between the water heating system and the management center via the communication network is possible.

A prestored program is executed in the communication adapter, thereby implementing the information collection function of collecting various pieces of information about the water heating system, the communication function of connecting to the communication network, the information transmission function of transmitting the information collected from the water heating system to the management center (server) by using these functions, and others. Therefore, by updating the program stored in the communication adapter, the functions of the communication adapter can be upgraded.

Japanese Patent Laying-Open No. 2009-286600 (PTL 2) describes that a program in operation is updated only when a result of self-diagnosis of a transmitted update program is normal at the time of update of a control program in a building monitoring system.

CITATION LIST

Patent Literature

PTL 1: Japanese Patent Laying-Open No. 2017-58026

PTL 2: Japanese Patent Laying-Open No. 2009-286600

SUMMARY OF INVENTION

Technical Problem

However, program update in a system where remote management involves communication between a management center (server) and a communication adapter as described in PTL 1 requires not only self-diagnosis of contents of an update program but also normal communication with the management center when the update program is executed.

The present disclosure has been made to solve the above-described problem, and an object of the present disclosure is to appropriately manage program update in accordance with a result of communication with an external apparatus after the program update, in a communication adapter applied to a remote management system for a hot water using facility using communication with the external apparatus.

Solution to Problem

According to an aspect of the present disclosure, a communication adapter connected to a hot water using facility via a communication line includes: a communication circuit; a memory; and a controller. The communication circuit receives and transmits information from and to an external apparatus via a communication network. The memory includes a plurality of program storage areas whose stored contents are rewritable. The controller operates the communication adapter by execution of a program stored in a specified one of the plurality of program storage areas. The communication circuit receives an update program from the external apparatus when a program update process is started up. When the program update process is started up during execution of a program stored in a first program storage area of the plurality of program storage areas specified at the time of a startup process, the controller executes a process of writing the update program received by the communication circuit into a second program storage area, the second program storage area being a program storage area of the plurality of program storage areas different from the first program storage area. When the process of writing ends normally, the controller specifies the second program storage area and re-executes the startup process, while retaining contents stored in the first program storage area. After the controller specifies the second program storage area and re-executes the startup process, the controller verifies whether or not communication with the external apparatus is possible, and when normal communication with the external apparatus is possible, the controller ends the program update process in a state in which the communication adapter is in operation by the update program.

According to the above-described communication adapter, it can be automatically checked that communication with the external apparatus (server) is normal and the program update process can be ended, in a state in which the update program for which the writing process has normally ended is in execution. Thus, program update can be appropriately managed in accordance with a result of communication after the program update.

Advantageous Effects of Invention

According to the present disclosure, program update can be appropriately managed in accordance with a result of communication with an external apparatus after the program update, in a communication adapter applied to a remote management system for a hot water using facility using communication with the external apparatus.

