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SETECNA S.r.l. – Via A.Volta, 19/B – 37062 – Dossobuono di Villafranca di Verona – VERONA – P.IVA 03200030231
SETECNA
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S.r.l.
Rev. 01
Alessandro
Page: 10 di 10
14/09/2016
23/09/16 17.56
Gateway MODBUS-to-Opentherm MB-OTG
Technical manual
4
Trableshooting
4.1
The Gateway Does not Power ON
Check the Power supply value and the polarity applied on the contacts “+” and “-“ of the Gateway;
if the poles have been inverted, the Gateway doesn’t Power ON.
The Gateway is equipped with self-resetting fuses: if has been applied an high value of Voltage or in
over-voltage case, this fuses may should have intervened. In that case it is necessary to disconnect
the Gateway from the power supply, waiting for the Fuse cooling and then reconnect the Gateway
to the Power Supply.
4.2
The Gateway does not communicate with the Master device
The LED “BUS” placed on the Front panel of the Gateway, turns ON and remain in this state for some
seconds when the Gateway receive a valid command from the MODbus.
In presence of Communication errors, first check if the LED “BUS” turns on (if the MODbus communication
is frequent, the led will be always on, on the contrary if the communication happens periodically the led
will turn on and then turn off again at every valid data received from MODBUS).
If the “BUS” LED does not turn on:
Check if the communication parameters on the MASTER device are correctly set, for more
information read paragraph 3.1 a pagina 5.
Check if the address number set on the Gateway corresponds with the address request from the
Master device.
Check that the Master is using the correct MODBUS functions during the communication with the
Gateway (especially the 0x03 for reading registers).
Check if the polarity of MODBUS connection is correct: because a unique standard of the Poles
labelling does not exist, it is possible that the poles on the Master device are not defined as “A” and
“B”, but as “+” and “-“ or with other label. In each case, try to invert the connection on the
Gateway and verify, by checking the “BUS” LED, if the communication starts; you should note that
even if on the Master the poles are marked as “A” and “B”, it may be an inverted convention unlike
the Gateway. So, in case of communication error, we always recommend to try to exchange the
connection on the MODbus poles.
