SICK TDC-B100, Operating Instructions Manual

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7 MONITORING
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8021804/2017-11-27|SICK T R A N S L A T I O N O F T H E O R I G I N A L I N S T R U C T I O N S | Telematic Data Collector
Subject to change without notice
7.5 Accessing data from the TDC device via the MQTT interface
7.5.1 Description of the MQTT interface structure
Sensor data from the individual TDC devices is accessed via the MQTT protocol. MQTT
communication here is based on the concept of topics. This involves each MQTT message
being assigned a topic that acts as a unique identifier for that message (for further
information on this, refer to Chapter
3.3 Interfaces for integration into customer
applications ).
Topics are simple strings that are separated by forward slashes to reflect a hierarchy of
sorts –similar to a simple URL.
TDC devices of the gateway system use the following topic structure:
Position No. Topic structure Explanation
1 Constant identifier Fixed value =
Wigo
2 IMEI of the TDC device See the TDC device
3 Directional information

out
: Data is sent from the TDC device

in
: Data has to be input in the TDC device
4 MQTT ID of the sensor Refer to the information in the configuration of the
sensor in question
Tab. 21: Topic structure of the MQTT protocol
If a TDC device with
123456789 as its IMEI were to send pressure measurements
configured with the MQTT ID Pressure 1 , the following topic would be assigned to the
message:
wigo/123456789/out/Pressure1
Measurement data is transmitted in text format with the numeric value followed by the
unit, e.g.,
4.5 kPa , 304 m, 0.045 kg .
Digital inputs are sent as note
1
for active and
0
for inactive.
From MQTT V 3.1, a user name and password can be assigned to the MQTT protocol.
Encryption can be taken care of over the network using SSL independently of the MQTT
protocol.
Ports
Port Explanation
1883 Standard port ( with IANA reserved for use with MQTT)
8883 Standard port ( use of MQTT with SSL encryption)
Tab. 22: MQTT standard ports
Example
Notes