Internal Temperature Measurement; Data Acquisition And Transfer - Phoenix Contact SCK-C-MODBUS User Manual

Solarcheck string current measurement with SCK-M-I-...
Using the analog connection for analog devices that are not part of the Solarcheck
device range
The data cable of any analog module with 0 ... 10 V, 0 ... 5 V or 2 ... 10 V standard signals
can be connected to the 0 ... 10 V input of the measuring module. Please note that
0 ... 10 V and 0 ... 5 V signals do not support the live zero function.
The supply output of the SCK-M-I-8S-20A is specifically tailored to the performance char-
acteristics of the SCK-M-U-1500V. Power supply to other devices is therefore not supported
or only supported to a limited extent and usually has to be implemented separately. When
designing this separate power supply, observe the relevant requirements from the data
sheet of the module to be connected.
Also observe the input resistance of the analog input (200 kΩ) if you want to connect analog
devices that are not part of the Solarcheck device range.
Make sure that the connected analog device is electrically isolated from the supply of the
remaining Solarcheck devices. Otherwise invalid values may occur on the analog input
side.
3.2.4

Internal temperature measurement

The internal device controller is equipped for temperature measurement. This means that
the device temperature inside the module can be monitored. The device is designed for op-
eration under temperature conditions ranging from -20°C .... +70°C. From experience, de-
pending on the ambient conditions (ventilation situation, etc.) the temperatures inside the
device are approximately 10°C above the temperature outside the device.
To that effect normal device operation is ensured if the temperatures measured inside indi-
cate ≤ 80°C. If the temperature inside the device exceeds 80°C, this may affect the function,
electronics, and service life of the device.
3.3

Data acquisition and transfer

The acquired data is transferred to the SCK-C-MODBUS Solarcheck communication mod-
ule via an internal communication cycle. A proprietary protocol is used for transmission. This
protocol also ensures that power is supplied to the measuring module. For this reason, it is
only possible to operate the current measuring modules via the corresponding SCK-C-
MODBUS Solarcheck communication module (Order No. 2901674). The Solarcheck cur-
rent measuring modules cannot be connected directly to a higher-level control unit.
The internal communication cycle ensures that the measuring data in the communication
module is updated very quickly within 2 s. The data is acquired and then transferred at the
request of the communication module. It is then available in the communication module for
a higher-level controller via Modbus. For further details on data retrieval, refer to Section
5.2.1 on page 33 and 5.2.2 on page 33.
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