Siemens RDG400 manual Multifunctional input, Digital input, Ai/Di

4.9Multifunctional input, Digital input

The thermostat offers two multifunctional inputs X1 and X2 and a digital input D1. A sensor of type NTC like QAH11.1 (AI, analog input) or a switch (DI, digital input) can be connected to the input terminals. The functionality of the inputs can be configured via parameters P38 for X1, P40 for X2, and P42 for D1.

#	Function of input	Description	Type	Type
			X1/X2	DI
0	Not used	No function.	--	--
1	External/Return	Sensor input for external room temperature sensor or	AI
	air temp.	return air temperature sensor to measure the current
		room temperature, or floor heating temperature
		sensor to limit the heating output.
		Note: The room temperature is measured by the built-
		in sensor if the floor heating limitation function is
		enabled via parameter P51.
2	Heat/cool	Sensor input for automatic heating / cooling	AI/(DI)	DI
	changeover	changeover function.
		A switch can also be connected rather than a sensor
		(switch closed = cooling, see section 4.6).
3	Operating mode	Digital input to switch over the operating mode to	DI	DI
	switchover	Energy Saving.
		If the operating mode switchover contact is active,
		user operations are ineffective and “OFF” is displayed.
4	Dewpoint monitor	Digital input for a dewpoint sensor to detect	DI	DI
		condensation. Cooling is stopped if condensation
		occurs.
5	Enable electrical	Digital input to enable/disable the electrical heater via	DI	DI
	heater	remote control.
6	Fault	Digital input to signal a fault.	DI	DI
		If the input is active, “ALx” is displayed
		(Alarm x, with x = 1 for X1, x = 2 for X2, x = 3 for D1).
		Note: Fault displays do not influence the thermostat's
		operation. They merely represent a visual signal.
		Example: dirty air filter

Operational action can be changed between normally open (N.O.) and normally closed (N.C.) via parameter P39, P41 (or P43 if it is a digital input).

Each input X1, X2 or D1 must be configured with a different function (1 … 5). Exception: one or two or three inputs may be configured as alarm inputs (6)

X1 is factory-set to “External sensor” (1), X2 to “Heating/Cooling changeover” (2), and D1 to Operating mode changeover (3).

For more information see section 4.5 “Applications”.

26 / 42

Siemens	RDG100…/RDG110…/RDG140.../RDG160… Basic Documentation	CE1P3182en
Building Technologies	Functions	28 May 2009