Page Comparison

Select whether to subscribe to the MQTT 'sys' topic. The 'sys' topic subscription is used to allow a remote host to send system level commands (see MQ_RBE_PR_Handler).

• sys/Gateway/# – issue subscription where "Gateway" is replaced by the Unit Name in the top-level System object (default, if Subscriptions object is omitted)
• sys/HCP_ID/Gateway/# – issue subscription where "Gateway" is replaced by the Unit Name, and HCP_ID is taken from the parent MQ_RBE object.
• Disable subscription to 'sys' topic – this option prevents 'sys' topics from being received on this device from a host. Note that this setting also prevents Health Echo commands, so an appropriate (non-Health Echo) option must be chosen for Host Synchronization. 

Select whether to subscribe to the MQTT 'cmd' topic. The 'cmd' topic subscription is used to allow a remote host to set or control data values in the FieldUnits on this device. This could be used in a situation requiring a field device to be monitored but commands must be explicitly prevented.

cmd/Gateway/# – issue subscription where "Gateway" is replaced by the Unit Name in the top-level System object (default, if Subscriptions object is omitted)

cmd/HCP_ID/Gateway/# – issue subscription where "Gateway is replaced by the Unit Name, and HCP_ID is taken from the parent MQ_RBE object.

Disable subscription to 'cmd' topic – this option prevents 'cmd' topics from being received on this device from a host. 

Select whether to subscribe to the MQTT 'file' topic. The 'file' topic subscription is used to allow a remote host to publish a file to this device via MQTT. This could be used with some additional logic to process configurations or other files.

file/Gateway/# – issue subscription where "Gateway" is replaced by the Unit Name in the top-level System object (default, if Subscriptions object is omitted)

file/HCP_ID/Gateway/# – issue subscription where "Gateway is replaced by the Unit Name, and HCP_ID is taken from the parent MQ_RBE object.

Disable subscription to 'file' topic – this option prevents 'file' topics from being received on this device from a host. 

Select how (or whether) to synchronize MQTT communication with a host system. Synchronization is typically used when this device is publishing through multiple MQTT servers, and one or more hosts is also connected to the MQTT servers. This ensures that the device and the host system are communicating with each other through the same MQTT server, so that commands and data are sent and received directly.

Require Health Echo from host – Host must periodically send out a 'sys' command with Health Echo and this device will respond with an echo, ensuring synchronized communication (default, if Subscriptions object is omitted). If the Health Echo is not received within two times the Keep Alive period configured in MQClient, the MQClient will disconnect from the current MQTT server and try the next address.

Subscribe to 'STATE/HostName' – (see Host Name option below) This synchronization method reduces network traffic by not requiring constant application-level Health Echo messages. 

In this case, the host should publish a message (with Retain flag set) with topic of "STATE/HostName" (where "HostName" is configured to identify the host). The payload of the message should be "CONNECTED" (all caps). It should also lodge a Last Will and Testament with the server using the same topic and a payload of "DISCONNECTED."

When a RediGate device connects to the server and subscribes to 'STATE/HostName', the server will deliver the retained message immediately with the payload "CONNECTED", thus informing the device that the host application is currently connect on the same server.

If this STATE message is not received within two times the Keep Alive period, the MQ Client will move to the next server. If the server disconnects from the server, the RediGate will receive the "DISCONNECTED" message and will immediately move on to the next server, attempting to locate a server to which the host is simultaneously connected.

No Host Synchronization – If only a single MQTT server is used, this option can be used. The MQ Client will not look for a Health Echo or STATE message but will remain connected to the server. Synchronization with a host is ensured as long as the host is also connected to the server. 

Select how to publish data on startup or upon reconnection to an MQTT server.

Send Only Non-Zero data registers – Upon connection, publish only non-zero values in RTDB registers (default, if Subscriptions object is omitted). Upon receiving the Birth Certificate from this device, the host must zero its entire database of values, so that non-zero data received from the device will ensure host and device have identical data. This option reduces the amount of published traffic upon connection.

Send All data including Zero/Null registers – Upon connection, all RTDB registers (except those configured as "Non-RBE") will be published even if they contain zeroes. This causes more data traffic on reconnection, but it ensures the host is informed of all available points, values, and identifications (tags or register numbers) at the time of connection. 

Select whether to publish tag names associated with RTDB register locations. Publishing registers with tag names requires the configuration of the optional Tag Names object under each RTDB (see 17629185).

Don't Publish Tag Names – Upon connection, publish only RTDB registers by number (default, if Subscriptions object is omitted). Upon receiving the Birth Certificate from this device, the host must zero its entire database of values, so that non-zero data received from the device will ensure host and device are in synch.

Publish Tag Names on MQTT Connect – Upon connection, publish a list of the configured Tag Names associated with RTDB register addresses for the Field Unit. Subsequently, all data will be published using the RTDB register addresses, but the host system can use the initial list to correlate addresses with names for display purposes.

Publish GZIP'd Tag Names on MQTT Connect – Same option as previous, but the initial publication of Tag Names and register addresses is sent in the MQTT payload in zipped format using 'gzip' compression. This reduces the bandwidth and packet size when publishing a large database of tag names. 

Enter the Host Name to use in the 'STATE/HostName' subscription, if using that option for Host Synchronization

Host Name must be NOTE: If any RTDB is configured to report by exception using Sparkplug-B but has no tag names configured, then all data for all RTDBs will be published, using their tag name (if available) or RTDB address. To prevent non-tagged registers from being published, make sure that all RBE RTDBs have at least one tag name configured.

Enter the Host Name to use in the 'STATE/HostName' subscription, if using that option for Host Synchronization

Host Name must be a maximum of 80 characters. If using the State/HostName option and this field is left blank, the Host Name in the subscription will default to the HCP_ID in the MQ_RBE object.

Must be 0.

Select which of four RBE flags to use for checking changed data (make sure not to use the same as any other process that might use the same RBE flag, such as MQTT, HCP, DNP).

The STATE topic is used to ensure an active end-to-end connection to Host, or switch to next MQTT server. In applications where the SCADA server and RediGate connect sequentially to more than one redundant MQTT broker, the SCADA server should publish the STATE topic to ensure the RediGate is in active communication using the same broker at the same time, to ensure RBE messages are received end to end. The RediGate will subscribe to the STATE topic, and if it doesn't receive 

To disable the use of the STATE topic, enter a string between 1 and 5 characters in length. Regardless of configuration, the STATE topic is ignored if the RediGate is only configured for a single MQTT server in the URL_List table.

The STATE topic is presently supported on the RediGate using the "legacy" format prior to the Sparkplug-B protocol version 3.0.0, where the payload is expected to be simple text as "ONLINE" or "OFFLINE". The STATE topic should be in the form "STATE/Host1", where "Host1" is the Primary Host ID in the Ignition MQTT Engine or equivalent in a different SCADA system (in MQTT Engine release 4.0.14 or later, also configure the Legacy Host ID - see STATE message in Sparkplug v3.0.0).