Stulz EC Tower ECD 91 - 4.2 Functions via the digital inputs; 4.3 Special functions

150 EN/01.2019/G22 © STULZ GmbH – all rights reserved
ec tower technical manual
4.2 Functions via the digital inputs
4.2.1 Evaluating the analog input
X2b-D4, analog input X3S is evaluated. Depending on the program,
the analog 010VDC signal is translated into a temperature or frequency setpoint. If there is no signal at
X2b-D4, the analog input is not evaluated. In this case, the corresponding setpoint can be specified via the
wired remote control.
Analog input evaluation is possible in the following programs:
- Program 8.
4.2.2 Remote ON/OFF
X2a-D1, the indoor air conditioning unit is switched on. If no signal is
present at X2a-D1, the indoor air conditioning unit is switched off.
Digital input X2a-D1 can also be set to forced mode (see “4.3.1 Forced mode“ on page 150).
4.2.3 Mode selection (Cooling/Heating/Fan)
If a signal is present at the corresponding digital input, the operating mode cannot be overridden by the wired
remote control. This affects Cooling, Heating or Fan modes, depending on the program.
Each program features mode selection. You can find further details on the correlation between operating
modes and digital inputs in the respective program description.
4.3 Special functions
4.3.1 Forced mode
D1 is continuously forwarded to the indoor
air conditioning unit via the X/Y remote control bus. The indoor air conditioning unit can then no longer be
switched using the corresponding wired remote control.
This function is enabled/disabled via DIP switch S25.
Forced mode can be enabled in the following programs:
- Program 8.
4.3.2 Inversion of digital outputs
DIP switch S26 determines the logical behavior of the relays. The relay switching function can be inverted
with DIP switch S26. Options “NO” and “NC” are available. The setting of DIP switch S26 always affects all
digital outputs simultaneously. It is not possible to invert a single digital output.
NO (normally open)
If no signal is present, the relay is de-energized and the contact is open. If a signal is present, the relay is ener-
gized and the contact is closed.
NC (normally closed)
If no signal is present, the relay is energized and the contact is closed. If a signal is present, the relay de-ener-
gizes and the contact is opened.
Inversion of digital outputs is possible in all programs.