Fronius Symo Series Operating Instructions Manual page 19

No. Function
Modbus RTU 2-wire (RS-485):
D- Modbus data -
D+ Modbus data +
Int./ext. power supply
- GND
+ U /U
int ext
Output for internal voltage 12.8 V
or
input for external supply voltage
> 12.8 - 24 V DC (+ 20%)
Digital inputs: 0 - 3, 4 - 9
Voltage level: low = min. 0V - max. 1.8V; high = min. 3V - max. 24V DC (+
20%)
Input currents: dependent on input voltage; input resistance = 46 kOhm
Digital outputs: 0 - 3
Switching capacity when supplied by the Fronius Datamanager 2.0 plug-
in card: 3.2 W in total for all 4 digital outputs
Switching capacity when supplied by an external power supply with min.
12.8 - max. 24 V DC (+ 20%), connected to Uint/Uext and GND: 1 A, 12.8
- 24 V DC (depending on the external power supply) per digital output
The connection to the I/Os is made via the supplied mating connector.
(8) Antenna plug
For screwing on the WLAN antenna
(9) Modbus termination switch (for Modbus RTU)
Internal bus termination with 120-ohm resistance (yes/no)
Switch in "on" position: Termination resistance of 120 Ohm active
Switch in "off" position: No termination resistance active
IMPORTANT! The termination resistance must be active for the first
and last device in an RS-485 bus.
(10) Fronius Solar Net master/slave switch
For switching between master and slave mode within a Fronius Solar
Net ring
IMPORTANT! All LEDs on the Fronius Datamanager 2.0 plug-in card are
off in slave mode.
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