JPH0439681B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a control device that performs control over a shared range in response to command data given via a transmission line from a host device such as a central control device. [Prior Art] Recently, in large-scale structures such as hotels and buildings, or large-scale production facilities, systems have been developed in which control devices are provided for each part or each control purpose, and these are centrally managed by a host device. Each control device is connected to a higher-level device by a transmission line, and performs control according to command data from the higher-level device. However, if command data from the higher-level device cannot be received due to a power outage, failure, abnormality in the transmission path, etc., the control device will respond to the failure on the higher-level device side in order to continue control by the control device. The system switches the judgment to a safe direction and continues control according to this judgment. However, with this method, for example, when the air conditioner is forced to stop operating during the day to cut peak power consumption, or during forced operation for the purpose of storing heat at night or for preheating in the early morning, a failure occurs on the host equipment side. If this occurs, the control device will start driving on the safe side because it is daytime, or stop driving on the safe side because it is night or early morning, and special commands will be ignored.
This results in drawbacks that are inconvenient for overall control. [Summary of the Invention] The present invention has an object of fundamentally solving the above-mentioned drawbacks of the conventional art, and stores reason data indicating the cause of generation of command data given from a host device in a memory together with the command data. The control contents are stored in the memory according to the reason data, and when the command data cannot be received, the reason data corresponding to the command data stored in the memory is read out from the memory, and this It is an object of the present invention to provide an extremely effective control device which reads control contents corresponding to reason data from the memory and performs control according to the contents. [Example] Hereinafter, the present invention will be explained in detail with reference to figures showing examples. FIG. 1 is a flowchart of the control situation by the control unit of the control device, and when a predetermined word representing command data etc. from a host device is not received for a certain period of time, a “predetermined word cannot be received?” 101 is used. Judging by a timer etc., this is YES
If so, perform a separate “timer start” 102,
In response to this “Time up?” 103 becoming YES, the target item (hereinafter referred to as point) i of the command data stored in the memory is set to the counter “i=
1" 104, and the reason data indicating the cause of the occurrence of the command data, which is previously stored in the memory in correspondence with the command data, is "read from the memory i's reason data" 105, and based on this, the "reason data "Reading the control contents according to the
After performing step 106, "update the control output of i according to the control content" step 107, thereby updating the control output data corresponding to point i in the memory,
If the question “i=n?” 108, which determines whether or not the above processing has been performed up to all points n, is NO, “i=i+
1” Register the counter with 109 and proceed to step 10.
Repeat steps 5 onwards. If the answer in step 108 is YES, the control output data in the memory is sent out for each point by "sending control outputs 1 to n" 110. Table 1 shows an example of reason data indicating the cause of generation of command data, to which each control content is added and stored in the memory.

【table】

Claims (1)

[Claims] 1. In a control device that performs control according to command data given from a host device via a transmission line,
A memory that stores command data from the higher-level device and reason data given from the higher-level device indicating the cause of the generation of the command data, and also stores control details at the time of backup according to the reason data, and an inability to receive the command data. The control unit further comprises a control unit that reads reason data corresponding to command data in the memory from the memory in response to the reason data, reads the control content corresponding to the reason data from the memory, and performs control according to the control content. control device.