Application

Overview
Room Unit Operation
7
Siemens Industry, Inc. Application Note, App 6689 140-0960
2015-10-05
Room Unit Operation
Sensor Select
SENSOR SEL is a configurable, enumerated point (values are additive). This point tells
the controller what type of room unit is being used and how to handle loss of
communication, for more information see Fail Mode Operation. It also provides the
ability to enable the optional RH and CO2 sensors and indicates which thermistor type
is connected.
Room Temperature, Setpoint, RH and CO2
 When the digital room unit (Series 2200/2300) is used, SENSOR SEL selects the
source for temperature and setpoint and enables a loss of communications
indication:
– 1 = enables supervision (from the room unit) for fail communications for
temperature and setpoint.
– 2 = enables supervision (from the room unit) for fail communications for relative
humidity.
– 4 = enables supervision (from the room unit) for fail communications for CO2.
 When the analog room unit (Series 1000/2000) is used, SENSOR SEL values for
temperature/setpoint, relative humidity and CO2 should be left at their default
values (0).
Thermistor Inputs
 Default for either input is 10K.
 To enable 100K Ω thermistor on input, see the following table for additive values.
SENSOR SEL
Value *
(additive)
Description
(include values to enable feature)
1 Select Digital Room Unit (for temperature sensing and setpoint dial)
2 Relative Humidity (RH) sensing
4 CO
2
sensing
8 If short board: 100K Ω thermistor on AI 3 (or input is 10K Ω)
If long board: 100K Ω thermistor on AI 5 (or input is 10K Ω)
16 Long board only: 100K Ω thermistor on AI 4 (or input is 10K Ω)
Example 1: Digital Room Unit with temperature, RH, CO2 and 10K thermistor.
1+2+4+0 = 7
Example 2: Analog Room unit with 100K thermistor. 0+0+0+8 = 8
Room CO2
RM CO2 displays the CO
2
value in units of parts-per-million (PPM). RM CO2 (from the
digital 2200/2300 room units) can be used with PPCL in the PTEC/ATEC controller or
unbundled for control or monitoring purposes.