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DATALOGGER
NI400
NI400
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DATALOGGER
NI400
NI400
The image above, illustrate the position of sensor’s terminal blocks. RS485 Modbus ter-
minal block is used for SmartModbus Sensors, while Channel 1 to 4 are used for analog
sensors.
RS485 SmartModbus Connection
NI400
can read digital sensor over the RS485 SmartModbus port.
The port used for sensors connection is RS485.
RS485 port presents 5 connections:
•(D-) Data – : can be named as B or “inverting pin” or TxD-/RxD-
• (D+) Data + : can be named as A or “non inverting pin” or TxD+/RxD+
• GND: it is the reference pin. It is recommended to use GND (SC, C, or reference pin)
while connecting RS-485 sensors.
• V+: NI400 can power RS485 sensors. It provides the same power source applied to NI400
VIN. Be careful to choose the right supply to power both datalogger and sensor.
• GND: same as V+, is the negative connection of power supply.
RS485 allows daisy chain connections. The example below shows an NI400 datalogger with
four temperature and humidity probes connected in daisy chain.
The
minimum distance
between two nodes (NI400 to probe, or probe to probe)
is 30 cm
.
WARNING: be careful on cable dimensions, as they are affected from total length and
probe numbers. Be sure to choose a cable of the right size for your project.
WARNING: Not all probes have a signal GND (SC) pin.
Digital Output
NI400 is provided with a Digital Output (NC / NO), which can drive low voltage (max 30V,
2A). It’s a relay, so it is a volt-free switch.
In order to handle higher voltages or currents, use internal relay to drive a rugged heavy
duty relay.
USB Host
Figure 8
Figure 9
Figure 10
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