Function of digital input/output (IO1 and IO2 ports)
The device has one multifunctional analog/digital input/output (between ports IO1 and IO2). Below, there's a summary of the available options for the functionality of the input.
SET/GET IO1/IO2 function:
There are 3 main logics for the IO1/IO2 input/output you can choose from:
Control the occupied/unoccupied status:
Option 1: Set-point decrease (changes the set-point to "unoccupied" & the fan and valve are based on the "unoccupied" set-point and current temperature in the room).
Option 2: Fan off, valve closed (does not change set-point, only forbids operation during unoccupied status)
The logic for all 3 options have their reversed counterpart in terms of the input to IO1 and IO2. E.g. 00 and 01 are the same, but the closed/opened logic is reversed. The logic is the same 02-03 and 04-05.
Occupancy sensor
Option 1: Set-point decrease
00: open β occupied, closed β unoccupied (set-point decrease) (default)
Command code 0x6200
It means that if the OCC port is opened, then the room is considered occupied. And if the OCC port is closed, then the room is considered unoccupied, temperature set-point and fan speed are decreased as described here.
01: closed β occupied, open β unoccupied (set-point decrease)
Command code 0x6201
Same basic logic as in 00, but reversed open/close status.
Option 2: Fan off, valve closed
02: open β occupied, closed β unoccupied (fan off, valve closed)
Command code 0x6202
Similar to 00 and 01, but set-point remains the same as the user has set and the FAN and valve are turned off.
03: close β occupied, open β unoccupied (fan off, valve closed)
Command code 0x6203
Same logic as 02, but reversed open/close status.
Dew point reached/not reached
04: closed β dew point reached, open β dew point not reached
Command code 0x6204
In case you have a dew-point sensor already installed in your FCU, then in this mode, the FCT can change the overall operation based on the sensor. If the OCC port is closed, then:
Dew-point alarm icon appears on the display
Dew-point alarm is sent in the keep-alive
General operation of the FCT is disabled, valve is closed, FAN is turned OFF
All keys are disabled before the OCC port is open again.
05: open β dew point reached, closed β dew point not reached
Command code 0x6205
Same logic as 04, but reversed open/close status.
Filter alarm
06: closed β filter alarm
Command code 0x6206
When the OCC is closed, then the device:
Shows an icon on the display for the filter
Continues normal operation
07: open β filter alarm
Command code 0x6207
Same logic as 06, but reversed open/close status
Defined by the application or automatic changeover:
In case you use an application (wiring diagram) with ECM fan OR you've decided to use the OCC for automatic change-over, then the OCC enters the following modes.
In those modes, you cannot change the function of the OCC unless you change the application or disable the automatic change-over
08: 10k NTC for auto changeover
Used case you want to use the auto changeover functionality. Read more about the settings of the automatic changeover here.
When the mode is changed from the changeover function, the command is sent together with the keepalive of the device. The keepalive data in the example below is omitted for clarity.
09: ECM Fan
In case your system has an ECM Fan, then the OCC port is used to control the fan and cannot be used for any other purpose. View available wiring diagrams (applications) here.
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