25
6.2 Trouble shooting
Table 6.2.1
Trouble shooting for 00.16131.501030 and 00.16131.501040
General
Inspect the instrument for any damage.
Inspect if the connector is properly attached.
Check the condition of the connectors (on chassis as well as the cable).
Inspect if the sensor receives DC voltage power in the range of 5 to 30 VDC.
Inspect the connection of the shield (typically not connected at the network side).
Inspect the connection of the sensor power supply, typically the negative is connected to the
network
common
.
Prepare for
indoor testing
Install a Modbus tool on a PC. Equip the PC with RS-485 communication. Put DC voltage
power to the sensor and establish communication with the sensor. At power–up the signal may
have a temporary output level different from zero; an offset. Let this offset settle down.
The sensor does
not give any
signal
Check if the sensor reacts to light: expose the sensor to a strong light source, for instance a
100 W light bulb at 0.1 m distance. The signal should read > 100 W/m
2
now. Darken the
sensor either by putting something over it or switching off the light. The instrument voltage
output should go down and within one minute approach 0 W/m
2
. Check the data acquisition by
replacing the sensor with a spare sensor with the same address.
Not able to
communicate
with the sensor
Check all physical connections to the sensor and try connecting to the sensor again. If
communicating is not possible, try to figure out if the address and communication settings are
correct. Analyse the cable performance by measuring resistance from pins to cable ends. The
electrical resistance should be < 10 Ω. In case of doubt,
try a new cable.
If all physical connections are correct, and the sensor still cannot be found, please contact the
factory to send the sensor to the manufacturer for diagnosis and service.
16131.5 does
not respond to a
request for 6 or
more registers
It is not possible to request more than five 16 bit registers in one request. In case of requesting
six or more registers in just one request, the sensor will not respond. If requesting six or more
registers, use multiple requests: the sensor will respond as expected.
The sensor
signal is
unrealistically
high or low
Note that night-time signals may be negative (down to -5 W/m
2
on clear windless nights in
standard operating mode), due to zero offset a.
Check if the pyranometer has clean domes.
Check the location of the pyranometer; are there any obstructions that could explain the
measurement result.
Check the orientation / levelling of the pyranometer.
Check the cable condition looking for cable breaks. Check the condition of the connectors (on
chassis as well as the cable).
The sensor
signal shows
unexpected
variations
Check the presence of strong sources of electromagnetic radiation (radar, radio).
Check the condition and connection of the shield.
Check the condition of the sensor cable.
Check if the cable is not moving during the measurement.
Check the condition of the connectors (on chassis as well as the cable)
The outer dome
shows internal
condensation
In case there is a minor layer of moisture that is hardly visible: Arrange to send the sensor to
the manufacturer for diagnosis and service.
The inner dome
shows internal
condensation
Arrange to send the sensor to the manufacturer for diagnosis and service.
