Examples of using Poseidon Industrial Bus

Industrial Bus (RS-485)

• Maximum cable length: 1000 m total
• Number of devices on the bus: Poseidon + up to 31 devices
• Power: 12V/120 mA supplied by the bus, can be boosted with an external adapter (through a S-Hub or a Spider unit).
• Cable type: UTP (2 or 3 pairs)

Topology 1: Basic

• The bus leads via a 4-wire connection from the Poseidon 1250 unit to two daisy-chained sensors, Temp-485 and HTemp-485. Two twisted pairs are used by the connection.
• A S-Hub unit is daisy-chain-connected via the RJ45 jack after the second sensor, using a 4-wire connection from the HTemp-485 sensor. The brown pair is used for power, the blue pair for data.
• Temp-485 and HTemp-485 sensors are connected to the S-Hub connectors 1 through 3 with 6-wire connections (brown pair for power, blue pair leads the bus to the device, green pair back from the device).
• Connector 4 of the first S-Hub unit is used to connect a Spider converter with a patch cable. The Spider unit is used to connect three Temp-1Wire 10m temperature sensors and one door contact (the contact is connected to the blue pair of the RJ45).
• A second S-Hub connects to the Spider unit output via a patch cable.
• Its connectors 1 through 3 are used to connect the Temp-485 and HTemp-485 sensors with 6-wire connections (brown pair for power, blue pair to the device, green pair back from the device).
• Connector 4 is used to connect a Temp-485 sensor with a 4-wire connection (brown pair for power, blue pair for the A/B signals of the bus).
• Termination is enabled at the Temp-485 sensor using the “TERM” jumper.

Topology 2: Connecting 10 sensors to IT Bus

Eight temperature sensors and two humidity sensors are connected via the IT Bus (RJ12) to a Poseidon 1250 unit. The 10 sensors are connected using two T-Box hubs and one T-Box2 unit.

• Bus used to connect the sensors: IT Bus

• Total bus length: 10m
• Maximum number of sensors: 10
• Sensors used:
  • 2x Humid-1Wire 1m
  • 8x Temp-1Wire 1m 
• Accessories used:
  • 2x T-Box
  • 1x T-Box2

Conclusion:

This solution is limited by the maximum IT Bus length. It is suitable for applications that use 1 to 10 sensors at one place (one location, 19” rack cabinet, etc.)..

Topology 3: Poseidon Spider – bus converter

The solution combines the properties of both buses. Two Spider units are far apart, connected via a Patch cable with RJ45 modular jacks. Both Spider units connect to four temperature or humidity sensors, each with a 10m cable. One Temp-485 sensor is located at the end of the chain and terminates the bus.

• One Temp-1Wire temperature sensor with a 10m cable is connected directly to the Poseidon unit to the RJ12 jack.
• Six temperature sensors and two humidity sensors are connected via the IT Bus (RJ12) to the Spider units. Each sensor is connected with a 10m cable.
• Two Spider units are connected to Poseidon 1250 with a standard RJ45 Patch cable using the Industrial Bus. Bus length is limited to 1000m.
• The Spider unit comprises 4 inputs for external sensors and supports one sensor per connector – for a maximum of 4 sensors.
• The Industrial Bus is terminated by connecting a Temp-485 sensor with termination enabled over a 4-wire connection. The Spiders have mutually different addresses and are set to the “middle” mode.

• Bus used to connect the sensors: IT bus, Industrial Bus
• Total bus length: 1000m + 9x 10m
• Maximum number of sensors: 40
• Sensors used:
  • 6x Temp-1Wire 10m
  • 2x Humid-1Wire 3m
  • 1x Temp-485
• Accessories used:
  • 2x Poseidon Spider
  • 2x RJ45 Patch cable 300m (RJ45-RJ45)
  • 1x RJ45 TP cable 300m (RJ45-4 pins, “LAST” wiring)

Conclusion:

This solution is not limited by the IT Bus length. The Spider units can be up to 1000m apart. The solution is suitable for large-scale applications with many sensors (e.g. server rooms).

Topology 4: Using the Industrial Bus – star topology

This solution demonstrates a star-like connection of sensors to the Industrial Bus using an S-Hub unit. The S-Hub is the central point that connects individual sensors. The maximum bus length decreases to 500m because the cable length of all sensors connected to the S-Hub must be counted twice. A Temp-485 sensor with termination is at the end of the bus.

• One Temp-1Wire temperature sensor with a 10m cable is connected directly to the Poseidon unit, to the RJ12 jack.
• The Industrial Bus connects to the S-Hub input via a RJ45 patch cable. At the same time, the cable powers the sensors as well as the S-Hub; extra power can be supplied by an external power adapter.
  • Sensors must be connected to the S-Hub in a sequence, starting from output No. 1. Outputs cannot be skipped. (For instance, connecting outputs 1,2,5,6 while leaving outputs 3 and 4 unconnected will not work.)
• First three temperature (Temp-485) and temperature/humidity (HTemp-485) sensors are connected in sequence to the first three outputs. An RJ45 / 6-wire cable, wired according to the “MIDDLE” version, is used to connect them.
• The Spider unit is connected with a Patch cord. The Spider connects four Temp-1Wire sensors at 4x 10m distances. The Spider unit is in the “MIDDLE” mode.
• The Industrial Bus is terminated at the Temp-485 sensor connected to the S-Hub at position No. 5. The connecting cable is wired according to the “LAST” version, termination is enabled at the sensor (Term=On).

Topology 5: Using the Industrial Bus – daisy chain

The solution demonstrates daisy-chain linked sensors on the Industrial Bus. Note the distances between sensors. The Spider unit connects four local temperature sensors. At the end of the bus, there is a Sens-UI voltage and current sensor with termination enabled.

• One Temp-1Wire temperature sensor with a 10m cable is connected directly to the Poseidon unit to the RJ12 jack.
• Two HTemp-485 temperature/humidity sensors are connected at the beginning of the bus, using a 4-wire cable connected to the terminals.
• The bus continues to the Temp-485 temperature sensor, still with 4 conductors.
• The Temp-485-Pt100-Cable uses a 4-wire connection as well. The temperature is measured by a Pt100 sensor mounted on a 2m silicon cable.
• The next Temp-485-Pt100-2xDIN converter, mounted on a DIN rail, uses a 4-wire connection. Two external Pt100 thermometers measure two temperature values.
• The following Temp-485-Pt100-Box sensor, designed for external environment, includes a probe for precise temperature measurement. 4-wire connection.
• The Spider unit is, on the contrary, connected via a RJ45 jack. The Spider connects four Temp-1Wire sensors located 4x 10m away.
• Please note the crossing of cables. It is necessary to respect the input and output designation of the RJ45 jacks. The Spider is in the “middle” mode.
• The Industrial Bus finally leads, via a 4-wire connection, to a Sens-UI sensor that measures external voltage and current.
• At this point, the bus is terminated by an external 120 Ohm resistor between the A and B pins.