Room Temperature Sensor RTS-20xxx (Rev 3.0) Installation & Application Guide
Page 4 of 13
Document Edition 2.3
Important Information
The Room Temperature Sensor RTS-20Jxx Service Port may be installed on a BACnet RS-
485 MS/TP or LINKnet network.
Note that this does not make the RTS-20Jxx a MS/TP or
LINKnet device; it simply adds a connection point to the network.
Depending on the model (S, P or SP) There are two inputs available to the controller from
the RTS-20xxx. One first is the push-button that simply shorts the sensing element causing
the temperature to read the highest or lowest value (based on Jumper setting) entered in the
scale range. Programming must be used to interpret this short as a depression of the push-
button and not an actual high or low temperature. See the Programming section for more
details. The second is a 20k
Ω
potentiometer for Setpoint adjustment that must also be
programmed and set by Jumper as required. See Setpoint Scaling for details.
Setpoint Scaling
(for Setpoint Adjustment)
The setpoint is adjusted using a linear 20k
Ω
potentiometer. In a typical 10k
Ω
analog input, to
get a linear response on the adjustment, use the
examples in the following table or create specific
scales using the equation: Value = Range * Dial
% + Offset
i.e. Value = 4° * 35% - 2° = -0.6°
In the scale table, look up the voltage associated
with 35% (2.31V) for the voltage side and put in
the value calculated into the value side of the
table.
~ Dial %
Voltage w/ 10K
± 2°
± 5°
0% (-)
0.00
-2
-5
0% 1.30 -2
-5
5% 1.49 -1.8
-4.5
10% 1.66 -1.6
-4
15% 1.81 -1.4
-3.5
20% 1.95 -1.2
-3
25% 2.08 -1
-2.5
30% 2.20 -0.8
-2
35% 2.31 -0.6
-1.5
40% 2.41 -0.4
-1
45% 2.50 -0.2
-0.5
50% 2.59 0 0
55% 2.67 0.2
0.5
60% 2.75 0.4
1
65% 2.82 0.6
1.5
70% 2.89 0.8
2
75% 2.95 1
2.5
80% 3.01 1.2
3
85% 3.06 1.4
3.5
90% 3.12 1.6
4
95% 3.17 1.8
4.5
100% 3.21 2 5
100% (+)
5.00
2
5
