Contemporary-control-systems BASremote Installation Guide Manual de usuario descargar pdf (Pagina 16)

TD040300-0II

excursions will be ignored. It is still possible to detect the input signal

by only sensing the positive excursions.

When interfacing to a pulse device that has an opto-isolated open-collector

output, a pull-up resistor must be added to the device output. In Figure 13,

a 3-phase wattmeter has three opto-isolated open-collector outputs, each

requiring an external pull-up resistor. Since each of the opto-isolators

is rated for 60 VDC, install a 100 kΩ pull-up resistor between each

output and the +24 V loop supply. The common of the opto-isolators

connects to the common of the BAS Remote. Since each BAS Remote

input has a 100 kΩ input impedance, the resulting voltage divider sets

the off-state voltage to 12 V. Even though the BAS Remote input

range is 0–10 VDC, this will not harm it. Set the two thresholds to 2 V

and 3 V. The threshold points on digital signals are not critical.

Consult the pulse device manual for more guidance.

Analog Input

Either voltage in the range of 0–10 VDC or current in the range of 0–20

mA can be measured with an analog input. Transmitters that produce

an elevated ―zero‖ such as 2–10 VDC or 4–20 mA can be measured as

well. Using the web page, configure the input for either voltage or

current and select an appropriate range. Scaling the input is accomplished

by assigning the low and high points to engineering units. When set as

a voltage input, the input impedance is 100 kΩ and for a current input,

the impedance is 250 Ω.

With voltage measurement, connect the more positive voltage to point

A and the less positive to BAS Remote common as shown in Figure 14.

On three-wire devices such as damper actuators, the output signal is

referenced to the damper’s power supply common. That common must

be at the same reference as the BAS Remote common. Notice the

connections in the diagram. In this situation it is only necessary to

attach the transmitter output to point A on the BAS Remote input.

When measuring current, remember the BAS Remote sinks current to

ground. A 250 Ω impedance is effectively applied between points A

and B on the input. To measure current, it must be driven into point A

with respect to point B. For two-wire current transmitters, the more

positive point on the transmitter attaches to the +24 V on the BAS

Remote loop supply or it can attached to an external loop supply as long

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Contemporary-control-systems BASremote Installation Guide Manual de usuario Pagina 16