iSMA-B-MINI/MIX BACnet User Manual
www.ismacontrolli.com
DMP261en | 1st Issue rev. 8 | 05/2022
page 59 of 114
the relevant COMMAND object. The outputs can be also overwritten by the DIGITAL
OUTPUT object, which allows remote control from the BMS.
Time Relay NO [s]
In this mode, if the output value is false, the rising edge on the digital input sets the
output to true. Every falling edge on the digital input restarts the counter, which means
that the output stays true for the time defined in the MODE TIME object (expressed in
seconds), counting from the last falling edge of the digital input. The action of the time
relay can be executed remotely by changing state from false to true in the relevant
COMMAND object. The outputs can be also overwritten by the DIGITAL OUTPUT object,
which allows remote control from the BMS.
Time Relay NC [s]
In this mode, if the output value is false, the falling edge on the digital input sets the
output to true. Every rising edge on the digital input restarts the counter, which means
that the output stays true for the time defined in the MODE TIME object (expressed in
seconds), counting from the last rising edge of the digital input. The action of time relay
can be executed remotely by changing state from false to true in relevant COMMAND
object. The outputs can be also overwritten by the DIGITAL OUTPUT object module, which
allows remote control from the BMS.
Input Forwarding
In this mode, any signal from the input is transferred directly to the assigned output
without any modifications. Operation in the input forwarding mode can be stopped by
the Block Input function.
Heating Mode (4U4O-H and 4U4O-H-IP Only)
In this mode, the output is controlled like a typical thermostat, basing on the Setpoint
object and the Control value (Input value) with differential parameter defined in the
Differential object. The output signal works in 2 states: low and high.
If the Control value is less than or equals to the difference between the Setpoint object
and Differential object, the output is in the low state.
If the Control value is greater than or equals to the sum of the Setpoint object and
Differential object, the output is in the high state.
The output in the low state:
Control value >= Se Differential
The output in the high state:
Control value <= Setpoint
–
Differential
The heating mode algorithm is shown in the chart below:
