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SETECNA
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Rev. 01
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Page: 9 di 10
14/09/2016
23/09/16 17.56
Gateway MODBUS-to-Opentherm MB-OTG
Technical manual
Examples:
To active the “Central Heating” (CH) function on the Boiler, set to value “1” the coil number 48.
To set the flow temperature setpoint of the Boiler on 55 °C, set to 550 the holding register number
25
To set the power limit to 70% for the Boiler, set to 700 the holding register number 27
Attention: To control the temperature boiler, the parameter “
Maximum relative modulation level setting”
(holding register 27), corresponding to Opentherm ID nr. 14, must be set out at value 1000 (corresponding
at the percentage value 100,0%). Lower values can prevent the Boiler to reach the expected temperature.
IMPORTANT NOTE: The OpenTherm standard does not require that the Boiler uses all the protocol IDs, so
it’s probable that one Boiler will not return all the previously shown information; in that case will be
returned a fixed value that means that the data is not used.
