Operating instructions
Gateway ZAbluegalaxy / DIG-2019NE
•
Appendices
L-BAL-312-GB 2020 Index 001
19/23
External Load Capabilities
+5V (USB)
Max. 500 mA per USB port, max 500 mA for all USB ports
Environmental Specifications
To specify an ambient operating temperature for reliable 24/7 industrial operation, the CPU and
GPU load are two very important factors. If all CPU cores are idle all the time, then the
maximum specified ambient temperature can be much higher than in a maximum CPU
utilization application.
The new BCM2837B0 system-on-chip has much more computation power than its
predecessors, but also gets far, far hotter. In high CPU load scenarios, the clock is dynamically
increased from 600 MHz to 1400 MHz and then produces so much heat, that even at room
temperature the clock would automatically throttle down to 600 MHz after several minutes to
prevent overheating.
Because of the thermal limitations of the used standard Raspberry Pi 3 Model B+ single board
computer, the form factor of the casing and the economic limitations in this entry level system,
no extensive passive cooling solution can be used. The internal baseboard designed by us
providing the power supply and the I/Os and two fieldbuses to the Raspberry Pi board, would
allow an ambient operating temperature from -25
…60°C but the Raspberry Pi board is the
limiting factor.
The embedded PC uses a passive heat sink on the BCM2837B0 chip and therefore is it not
possible to use all of the computation performance the BCM2837B0 provides. The system
power consumption ranges from 3.0 W (average when idle) to 9.5 W (maximum under stress).
To prevent CPU overheating and throttling, the maximum system power consumption should
not be higher than about 4 W. In most real world use cases of this embedded computer, the
average power consumption will be lower than this limit, but if constant CPU performance is
important for your application, then limiting the maximum CPU frequency to 600 MHz in
configuration file /boot/config.txt is one possibility to achieve this. Without limiting the maximum
CPU frequency, the CPU will dynamically change the frequency depending on the CPU
temperature (see commands:
vcgencmd measure_temp
and
vcgencmd measure_clock arm
).
Ambient operating
Temperature
0 .. +40 °C (vertical orientation / wall and DIN rail mounting)
0 .. +35 °C (horizontal orientation / desk-top mounting)
at sea level, derated by 1 °C per 300 m above sea level to
a maximum of 2000 m.
the above temperature ratings are defined under the following CPU
load:
•
No GPU load
•
4 cores loaded at 600 MHz or 1 core loaded at 1400 MHz,
where the load per core is comparable to that of the Linux
stress-ng utility
•
The above numbers are without safety margins to
compensate process variations of the Broadcom SoC
•
More load will bring the CPU Junction temperature above
80°C and the CPU will reduce clock frequency towards 600
MHz. The system will not overheat under such conditions.
Temperature storage
-20
…+75 °C
Humidity
5
…95 % r.H., non condensing
Protection Class
IP20
Physical Dimensions
Size (WxHxD)
99.8 x 30.0 x 96.7 mm
Weight
200 g
