Contemporary Control Systems BAScontrol20 Installation Guide - Manual (Page 7)

TD100700-0IA
7
Universal Input — Configured for Analog Input
A Universal Input can measure voltage in the range of 0–10 VDC or current in
the range of 0–20 mA with the use of an external resistor. Transmitters that
produce an elevated “zero” such as 2–10 VDC or 4–20 mA can be measured
as well. With a web browser, access the Main Screen, click the title link of
any channel UI1–UI8. Then set the Channel Type to Analog Input and the
Units to either AMPERES or VOLTS. The input impedance is 1 MΩ.
To measure voltage, connect the more
positive wire to point A. The output of
a three-wire device (such as the actuator
in Figure 4) references its power
supply common — which must match
the BASC20 common. In this
situation, you only need to attach the
device output to input point A on the
BASC20 — otherwise, tie the negative
wire to point C.
When measuring current (UI2 in
Figure 4), provide a 500 Ω resistor
between points A and C to measure a 0–20 mA signal with full resolution.
Universal Input — Configured for Temperature Input
Built-in calibration curves are provided for 10 kΩ Type II or Type III
thermistors. With a web browser, access the Main Screen, click the title
link of any channel UI1–UI8. Then set the Channel Type to either
Therm 10KT2 or Therm 10KT3 and the Units to either
DEGREES_CELSIUS or DEGREES_FAHRENHEIT.
As shown in Figure 5, connect the thermistor to
points A and C. Polarity is not an issue. For
temperature averaging, connect multiple devices of
the same in a series-parallel combination so that the
nominal resistance remains at 10 kΩ. The effective
range of temperature measurement for Type II 10
kΩ thermistors is from –10º to +190 ºF (–23.3º to
+87.8ºC). For Type III 10 kΩ thermistors it is from
–15º to +200 ºF (–26.1º to +93.3ºC). The channel
LED will glow when a thermistor is properly connected.
Figure 4 — Analog Input Connections
Figure 5 —
Thermistor
Connections