Herz pelletfire, Руководство по эксплуатации

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11 Description of the menu navigation and adjustment values
58 Betriebsanleitung_pelletfire_Touch_Englisch_V1.2
External requirement at digital input:
At a digital request the external set temperature gets transmitted as value to the heat supplier.
External requirement at analogue input:
At an analogue request a calculated (= linearly interpolated) temperature gets transmitted to the heat
supplier (see Figure 12). The graph in Figure 12 gets regulated by
the parameters „analogue must
temperature 4 mA“ and „analogue must temperature 20 mA“.
For example at an analogue request with an current signal of 12 mA, a temperature of 60 °C is registered at
the heat supplier, provided that the digital requirement (= external must temperature) is not higher.
a.) Figure 12.19 : Analogue must temperature as a function of the applied current
signal of the external requirement
At the input of the external requirement module a current signal between 4 and 20 mA should be given,
because a current signal is compared to a voltage signal insensitive to electromagnetic disturbances and
voltage losses at the cables. With an internal resistor (500 Ohm) the current signal is converted into a
voltage signal.
b.) Figure 11.20: Input signal of the external requirement module
External requirement
module
500 Ω
Input signal =
current signal
An
alog
mu
st t
emp
e
ratu
re
[
°C
]
Current signal [mA]