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| Parameter | Description | Unit / size | Default value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Activates detailed debug information about sending and receiving values. | YES/NO | NO | ||||||
| User name used in a CONNECT message to connect to the MQTT server. | - | |||||||
| Password used in a CONNECT message to connect to the MQTT server. | - | |||||||
| The name of one topic or a multiple topic filter sent within the SUBSCRIBE message. Using the filter the MQTT client specifies topics, within which it wants to receive messages. Note: topics are hierarchically sorted, a slash (/) is used as the separator, a plus (+) is used as a one-level mask, a hash (#) character is used as a mask for multiple levels. Examples of filter: a/b , level1/+ , # , +/+/+/up | - | # | ||||||
| The desired maximum level of validation (QoS) sent within the SUBSCRIBE message. The MQTT server can then send PUBLISH messages with such or lower levels of confirmation (but not higher). PUBLISH messages sent by the MQTT server will be confirmed by the D2000 KOM process according to the level of confirmation specified in them. The higher the level of confirmation, the more messages between the client and the server are exchanged (1 at QoS_0, 2 at QoS_1 and 4 at QoS_2). | QoS_0 QoS_1 QoS_2 | QoS_1 | ||||||
| Unique client identifier (Client Identifier) sent within the CONNECT message. The tested MQTT server (thethings.network) returned an error if the Client ID was blank and Clean Session Flag=NO. | - | |||||||
| Parameter Clean Session Flag of the CONNECT message. The No value means that the server uses the current session state (connection) - e. g. after collapse and recovery of the TCP connection. This means that all unconfirmed PUBLISH messages with QoS_1 and QoS_2 are resent (optionally also QoS_0, depending on the implementation). The Yes value means that the session is re-created and unconfirmed PUBLISH messages are not repeated. | YES/NO | NO | ||||||
| Level of confirmation (QoS) used to send PUBLISH messages through the D2000 KOM process. Sending the PUBLISH message is the outcome of writing into the output tag with the OUT_DATAVALUE address. The higher the confirmation level, the more messages between the client and server are exchanged (1 for QoS_0, 2 for QoS_1, and 4 for QoS_2). | QoS_0 QoS_1 QoS_2 | QoS_0 | ||||||
| Setting the Retain flag used when sending PUBLISH messages by the D2000 KOM process. Activating the Retain flag causes the last message sent by the D2000 KOM process to be available on the MQTT server to other clients immediately after they are connected, as well as after the D2000 KOM process is disconnected. | YES/NO | NO | ||||||
| If the MQTT server did not send any message during the specified time interval, the D2000 KOM process sends a PING request and waits for a PING response (until time Reply Timeout). A value of 0 turns off sending the PING request messages. The parameter allows detection of TCP connection failure. | sec | 60 | ||||||
| The setting of message parsing:
| Text only JSON | Text only | ||||||
| Parameter Will Flag of a CONNECT message. A value of Yes means that the server will send a Last Will message to interested parties if the connection to the D2000 KOM process is lost. | YES/NO | NO | ||||||
| The acknowledgment level (QoS) used when sending a Last Will message in the event of a loss of connection to the D2000 KOM process. | QoS_0 QoS_1 QoS_2 | QoS_0 | ||||||
| The setting of the Retain flag used when sending a Last Will message if the connection to the D2000 KOM process is lost. | YES/NO | NO | ||||||
| The topic used to send the Last Will message if the connection to the D2000 KOM process is lost. | - | |||||||
| Contents of the Last Will report if the connection to the D2000 KOM process is lost. | - | |||||||
| If the MQTT server does not respond to the SUBSCRIBE, UNSUBSCRIBE, and PING requests within the required time or the D2000 KOM process fails to read a complete message (and only part of it is read), the D2000 KOM process declares an error, closes the connection, and opens it again. Value 0 turns off the timeout. | sec | 20 | ||||||
| A timeout of a single reading from a TCP connection. D2000 KOM repeats reading of spontaneous data Max. Wait Retry times and if no data is read, the reading is timeouted and finished (and may be followed by a further reading or writing). By lowering Wait Timeout and Max. Wait Retry parameters, it is possible to achieve a faster writing response of the D2000 KOM process at the expense of a higher CPU load when the MQTT server has no data. | sec | 0.100 | ||||||
| The number of repetitions of reading from TCP connection. See the description of the Wait Timeout parameter. | - | 3 |
...
| Type of I/O tag | Address | Description | ||||||
|---|---|---|---|---|---|---|---|---|
| I/O tags for reading data sent by MQTT server through PUBLISH message. Note: values of I/O tags are set by the D2000 KOM process in the order IN_TOPIC, IN_DATA and IN_ID. It is not necessary for configuration to contain all three I/O tags. | ||||||||
| TxtI |
| Topic (Topic) of received PUBLISH message. | ||||||
| TxtI |
| Data (Payload) of received PUBLISH message. | ||||||
| Ci |
| Identifier of a packet (Packet Identifier) of PUBLISH message that depends on the level of validation (QoS). For messages sent with QoS_0, the identifier is zero, for QoS_1 and QoS_2, it is a positive 16-bit number. Note: if the MQTT server sends also messages with the QoS_0 level of validation and the ACK_ID I/O tag is configured, then we recommend activating the option New value when changing time in the Filter tab, so that repeated writing of the value 0 will cause a new value that differs only in a timestamp to be generated. | ||||||
| I/O tags for parsing JSON messages | ||||||||
TxtI, TxtO, Qi, |
| If Payload Type=JSON, the message is parsed as JSON data. The json_address value specifies the name of the JSON field whose value is to be assigned to the I/O tag. | ||||||
| I/O tag to confirm the received data to the MQTT server. | ||||||||
| Co |
| If an output I/O tag with ACK_ID address is defined, the D2000 KOM expects confirmation of the processing of each message by writing a copy of the value of the IN_ID tag. Only after, it sets values from the next received PUBLISH message (if it was received in the meantime) into the IN_TOPIC, IN_DATA, and IN_ID I/O tags (in this order). In the case of the QoS_0 level of confirmation, it is, therefore, necessary to repeatedly set the value of I/O tag ACK_ID to 0. If the I/O tag ACK_ID does not exist, the values are written into the IN_TOPIC, IN_DATA, and IN_ID I/O tags immediately after the PUBLISH message is received and processed. Note: for the messages received with the QoS_0 level of validation, no confirmation is sent to the MQTT server, only the values of the received PUBLISH message will be published. | ||||||
| I/O tags for sending values to the MQTT server through PUBLISH message. Note: in order for the D2000 KOM process to send the PUBLISH messages to the MQTT server, both I/O tags must be defined within one station. | ||||||||
| TxtO |
| The topic of the PUBLISH message being sent. | ||||||
| TxtO |
VALUE | Data (Payload) of the PUBLISH message being sent. Note: sending the message is performed out as a result of writing to the OUT_DATA VALUE I/O tag (i.e. if the Topic does not change then it is sufficient to set the OUT_TOPIC point once - e.g. by using default value). | ||||||
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