020
www.ruggedaq.com
1
DATALOGGER
NI2400
NI2400
021
www.ruggedaq.com
1
DATALOGGER
NI2400
NI2400
Digital Output Connection
NI2400 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.
RS485 SmartModbus Connection
NI2400 can read digital sensor over the RS-485 SmartModbus port.
The port used for sensors connection is RS-485#1.
WARNING: RS-485#2 PORT DOES NOT WORK WITH DIGITAL SENSORS AS IT IS
DESIGNED TO WORK ONLY WITH MULTIPLEXERS.
RS-485#1 port presents 5 connections:
• Data – : can be named as B or “inverting pin” or TxD-/RxD-
• 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: NI2400 can power RS485 sensors. It provides the same power source applied to
NI2400 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.
RS-485 allows daisy chain connections. The example below shows an NI2400 datalogger
with four temperature and humidity probes connected in daisy chain.
Figure 20
The
minimum distance
between two nodes (NI2400 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.
Example
Figure 21
Not all probes have a signal GND (SC) pin, and in the example above, the probe was not
connected to signal ground.
Multiplexers Connection
NI2400 offers Analog Sensors expandability through Multiplexers.
Multiplexers are expansion boards that can read up to 24 sensors each, with connections
logic similar to NI2400 (explained in Multiplexer Section), which will be connected to chan-
nel 22/23/24 of NI2400.
More than one Multiplexer can be connected to NI2400, up to 16 Units, daisy chained to
RS-485#2 and channels 22/23/24.