• string.bloxx AIO 24/12

string.bloxx AIO  24/12  (all-in-one solution)

Effective PV Monitoring requires constant, solid and traceable PV Plant monitoring data in order to determine actual performance and fulfil owner/investor expectations. Operators are interested to identify errors and losses in a reliable way to trigger appropriate actions for maximizing energy harvest during the total system lifetime. With the monitoring of PV Module strings, design and production errors will be recognized on the DC side with high resolution down to PV Module level.

Using DC shunts (vs. Hall Effect sensors) the string.bloxx provides current measurements typically 10 times more accurate and not susceptible to temperature variance. This equates to higher accuracy measurements and better understanding of true system performance. In addition, string voltage (up to 1000V) and DC power on every string can be continuously monitored ensuring maximum system productivity.

Continuous measurement of both cabinet and panel temperatures, along with overvoltage monitoring and main switch control greatly and improves system diagnostics.

This accurate measurement is inverter independent and gives feedback about losses due to inverter malfunction, soiling, shading, PV Module degradation etc. .

The string.bloxx communication uses industry standard Modbus protocols for easy and fast integration and reliable data exchange with the data logger. For longer communication distances fiber optic technology is used.

The benefits of string.bloxx AIO 24/12:

  • The All-In-One Solution improves your Project ROI and offers increased local content
  • Unifies DC measurement, fuses, overvoltage protection & communication
  • Significant reduction of interfaces leads to reduced risk and faster plant installation time

Key features

Connection for strings Up to 24 PV strings
24 String current inputs ± 13 A String current, ± 312 A summary @ 60°C
48 PV fuses incl. fuse holders 15 A (typical) or based on customer requirements, positive and negative side
 Inputs for current measurement 12 Analog inputs for current measurement
± 26 A string current (calibrated)
Analog input channel for voltage measurement 1 channel, 0-1000 VDC string voltage
 Temperature sensor 1 On board temperature sensor
cabinet temperature
VDC Layout On board 1000 VDC SPD, RS 485 SPD
 2 Digital inputs Monitoring of overvoltage protection and main switch
 Signal conditioning Calculated DC Power, linearization, mean value, scaling, alarm
RS485 fieldbus interface Up to 115.2 kbps: Modbus-RTU, ASCII (optional OEM protocols)
Connectivity Data logger (e. g. Q.reader) and gantner.webportal for worldwide access or other 3rd party applications

Functional Scheme


Input Current
Max. Number 24
Max. Current ± 13 A
Connection 0.25 mm2 - 6 mm2 push-in spring-cage connection
Current measurement
Max. Number 12
Range ± 26 A
Accuracy 0.25 %
Voltage measurement
Number 1
Range 0-1000 VDC
Accuracy 0.2 %
Connection 0.25 mm2 - 6 mm2 push-in spring-cage connection
Input cabinet temperature
Number 1
Type Digital, onboard
Range -40 °C till +125 °C
Accuracy ± 0.5 K
Digital Inputs
Number 2
Input State
Connection 0.25 mm2 - 1.5 mm2 push-in spring-cage connection
Power Supply
Power supply 10 up to 55 VDC, overvoltage and overload protection
Power consumption approx. 1.5 W (0.4W at 30 seconds sample rate)
Connection 0.2 mm2 - 2.5 mm2 push-in spring-cage connection
Communication Interface
Standard RS-485, 2-wire
Data format 8n1
Protocols Modbus-RTU: 19.200 bps (default), range: 9.600 bps up to 115.200 bps
Number of devices on the bus max. 250
Connection 0.2 mm2 - 2.5 mm2 push-in spring-cage connection
Overvoltage protection PV section Overvoltage arrester 2 / II acc. to EN 61643-11 / IEC 61643-1/-11
Nominal surge current: (8/20) 20 kA

with 3-stage DC- switch for PV Power Plants, up to 1000VDC
Overvoltage protection Communication (RS485) Gas Discharge Tube - GDTs / Gas-Plasma-arrester mini trigard symmetrical SMT;
Peak- impulse-current: 10 kA, 600 Watt Transient Voltage Suppressors
Electromagnetic Compatibility According to EN 61000-4 and EN 55011
Relative humidity 5 % up to 95 % at 50°C, non-condensing
Operating temperature -20°C up to +60°C @ max 312 A current
Storage temperature -40°C up to +85°C
Relative humidity 5 % up to 95 % at 50°C, non-condensing
Dimensions (L x W x D) (450 x 321 x 55) mm
Weight approx. 2800 g