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Concept Concept 3/8/2017
Products: AS-B
Functionalities: Hardware
Product version: 1.8, 1.9

Universal Inputs/Outputs

The universal inputs/outputs are ideal for any mix of temperature, pressure, flow, status points, and similar point types in a building control system.

As counter inputs, the universal inputs/outputs are commonly used in energy metering applications. As RTD inputs, they are ideal for temperature points in a building control system. As supervised inputs, they are used for security applications where it is critical to know whether or not a wire has been cut or shorted. These events provide a separate indication of alarms and trouble conditions to the system.

The universal inputs/outputs are capable of supporting analog outputs of type voltage outputs. Therefore, the universal inputs/outputs support a wide range of devices, such as actuators.

The AS-B's universal inputs/outputs consist of two types: Ua and Ub. The difference between the two types of universal inputs/outputs is that the Ub type supports current inputs.

Inputs

The universal inputs/outputs can be configured to read several different types of inputs:

  • Digital

  • Counter

  • Supervised

  • Voltage

  • Current (Ub only)

  • Temperature

  • Resistive

  • 2-Wire RTD temperature

  • 2-Wire RTD resistive

Input internal configuration

Input internal configuration

Applied voltages beyond the absolute maximum ratings will cause over current in the protection component D Z .

Digital inputs

The external connection of a digital input is shown in the following figure.

Digital input external connection

Digital input external connection

K is the monitored external switch.

V S = 24 V

R PU = 10 kohm

Counter inputs

A counter input utilizes the same hardware configuration as the digital input as shown in the figure above.

Supervised inputs

Supervised inputs are contact closing inputs supplemented with the supervision of the field wiring integrity. This supervision is a required feature in many security system applications. The supervised inputs provide the ability to detect specific forms of tampering or trouble with the wire connections to the field contacts. The supervision is achieved with a combination of 1 or 2 resistors attached to the contact in the field. The resistor combination creates continuous current flow through the field contact loop and presents a defined set of expected resistance values for each of the defined conditions. If someone is attempting to defeat the monitoring of the field contact by short circuiting the wire with a jumper or cutting the wire, the objective is to detect and indicate such a condition. The resistors need to be located at the end of the cable close to the field contact, so that the point where there is a risk that the circuit is defeated is between the resistors and the I/O.

Three different types of supervised input connections are supported:

  • Series only

  • Parallel only

  • Series and parallel

Each type of supervised input connection provides a different capability in regards to what form of tamper/trouble can be detected regardless of switch contact open or closed condition.

A single resistor, which is connected in series with the switch, can only detect tamper/trouble in the form of a short circuit across the wire pair. The external connection of a series only supervised input connection is shown in the following figure.

Series only external connection

Series only external connection

K is the monitored external switch.

V S = 5 V

R PU = 10 kohm

A single resistor, which is connected in parallel with the switch, can only detect tamper/trouble in the form of an open circuit in the field wiring loop. The external connection of a parallel only supervised input connection is shown in the following figure.

Parallel only external connection

Parallel only external connection

K is the monitored external switch.

V S = 5 V

R PU = 10 kohm

Two resistors, where one is connected in series with the switch and one is connected in parallel with the switch, can detect tamper/trouble conditions in the form of both an open and a shorted circuit. The external connection of a series and parallel supervised input connection is shown in the following figure.

Series and parallel external connection

Series and parallel external connection

K is the monitored external switch.

V S = 5 V

R PU = 10 kohm

Voltage inputs

The external connection of a voltage input is shown in the following figure.

Voltage input external connection

Voltage input external connection

V G is the monitored external voltage.

R IN = 100 kohm

Current inputs

The external connection of a current input is shown in the following figure.

Current input external connection

Current input external connection

I G is the monitored external current.

R SH = 47 ohm

In the internal configuration of the current input, there is a current limit circuit in order to protect the shunt resistor from over load. The input current is limited to 60 mA with a serial connected FET transistor. If this limit is reached for 0.5 s, the transistor is turned off. When 5 s has elapsed, the transistor is turned on again to make a new start attempt.

Temperature inputs

The external connection of a temperature input is shown in the following figure.

Temperature input external connection

Temperature input external connection

R T is the monitored external thermistor.

When a universal input is used as a temperature input, V S and R PU in the internal configuration of the universal input are used according to the following table.

Thermistor type

V S

R PU

20 kohm

5 V

10 kohm

10 kohm

5 V

10 kohm

2.2 kohm

1 V

1.5 kohm

1.8 kohm

1 V

1.5 kohm

1 kohm

1 V

1.5 kohm

The resulting voltage across the thermistor is measured and a temperature is calculated dependent on the selected thermistor type.

Resistive inputs

The external connection of a resistive input is shown in the following figure.

Resistive input external connection

Resistive input external connection

R M is the monitored external resistance.

V S = 5 V

R PU = 10 kohm

2-wire RTD temperature inputs

The external connection of a 2-wire RTD temperature input is shown in the following figure.

2-wire temperature input external connection

2-wire temperature input external connection

R T is the monitored external RTD.

R W is the wiring resistance.

V S = 1 V

R PU = 1.5 kohm

When an input is used as a 2-wire RTD temperature input, you need to state the wiring resistance in the software.

The resulting voltage across the RTD is measured, and the temperature is calculated dependent on the selected RTD type.

2-wire RTD resistive inputs

The external connection of a 2-wire RTD resistive input is shown in the following figure.

2-wire RTD resistive input external connection

2-wire RTD resistive input external connection

R T is the monitored external resistance.

R W is the wiring resistance.

V S = 1 V

R PU = 1.5 kohm

When an input is used as a 2-wire RTD resistive input, you need to state the wiring resistance in the software.

The resulting voltage across the RTD is measured, and the resistance is calculated dependent on the selected RTD type.

The RTD resistive input type is used to measure the resistance of an RTD other than the supported types. The resistance to temperature conversion must be performed in a function block or script program in the device.

Outputs

The universal inputs/outputs can be configured as voltage outputs.

Voltage output internal configuration

Voltage output internal configuration

R OUT is approximately equal to 10 ohm.

Specifications
Channels, AS-B with 24 I/O points
12 Ua, Ua1–Ua12
  
4 Ub, Ub1–Ub4
Channels, AS-B with 36 I/O points
20 Ua, Ua1–Ua20,
  
8 Ub, Ub1–Ub8
Absolute maximum ratings
-0.5 to +24 VDC
A/D converter resolution
16 bits
Digital inputs
Range
Dry contact switch closure or open collector/open drain, 24 VDC, typical wetting current 2.4 mA
Minimum pulse width
120 ms
Counter inputs
Range
Dry contact switch closure or open collector/open drain, 24 VDC, typical wetting current 2.4 mA
Minimum pulse width
20 ms
Maximum frequency
25 Hz
Supervised inputs
5 V circuit, 1 or 2 resistors
Monitored switch combinations
Series only, parallel only, and series and parallel
Resistor range
1 to 10 kohm
For a 2-resistor configuration, each resistor is assumed to have the same value +/- 5 %
Voltage inputs
Range
0 to 10 VDC
Accuracy
+/-(7 mV + 0.2 % of reading)
Resolution
<0.5 mV
Impedance
100 kohm
Current inputs
Range
0 to 20 mA
Accuracy
+/-(0.01 mA + 0.4 % of reading)
Resolution
<1 μA
Impedance
47 ohm
Resistive inputs
10 ohm to 10 kohm accuracy
+/-(7 + 4 x 10 -3 x R) ohm
R = Resistance in ohm
10 kohm to 60 kohm accuracy
+/-(4 x 10 -3 x R + 7 x 10 -8 x R 2 ) ohm
R = Resistance in ohm
Temperature inputs (thermistors)
Range
-50 to +150 °C (-58 to +302 °F)
Supported thermistors
Honeywell
20 kohm
Type I (Continuum)
10 kohm
Type II (I/NET)
10 kohm
Type III (Satchwell)
10 kohm
Type IV (FD)
10 kohm
Type V (FD w/ 11k shunt)
Linearized 10 kohm
Satchwell D?T
Linearized 10 kohm
Johnson Controls
2.2 kohm
Xenta
1.8 kohm
Balco
1 kohm
Thermistor accuracy
20 kohm
-50 to -30 °C: +/-1.5 °C (-58 to -22 °F: +/-2.7 °F)
  
-30 to 0 °C: +/-0.5 °C (-22 to +32 °F: +/-0.9 °F)
  
0 to 100 °C: +/-0.2 °C (32 to 212 °F: +/-0.4 °F)
  
100 to 150 °C: +/-0.5 °C (212 to 302 °F: +/-0.9 °F)
10 kohm, 2.2 kohm, and 1.8 kohm
-50 to -30 °C: +/-0.75 °C (-58 to -22 °F: +/-1.35 °F)
  
-30 to +100 °C: +/-0.2 °C (-22 to +212 °F: +/-0.4 °F)
  
100 to 150 °C: +/-0.5 °C (212 to 302 °F: +/-0.9 °F)
Linearized 10 kohm
-50 to -30 °C: +/-2.0 °C (-58 to -22 °F: +/-3.6 °F)
  
-30 to 0 °C: +/-0.75 °C (-22 to +32 °F: +/-1.35 °F)
  
0 to 100 °C: +/-0.2 °C (32 to 212 °F: +/-0.4 °F)
  
100 to 150 °C: +/-0.5 °C (212 to 302 °F: +/-0.9 °F)
1 kohm
-50 to +150 °C: +/-1.0 °C (-58 to +302° F: +/-1.8 °F)
RTD temperature
Supported RTDs
Pt1000, Ni1000, and LG-Ni1000
Pt1000
Range
-50 to +150 °C (-58 to +302 °F)
Accuracy
-50 to +70 °C: +/-0.5 °C (-58 to +158 °F: +/-0.9 °F)
  
70 to 150 °C: +/-0.7 °C (158 to 302 °F: +/-1.3 °F)
Ni1000
Range
-50 to +150 °C (-58 to +302 °F)
Accuracy
+/-0.5 °C (+/-0.9 °F)
LG-Ni1000
Range
-50 to +150 °C (-58 to +302 °F)
Accuracy
+/-0.5 °C (+/-0.9 °F)
RTD temperature wiring
Maximum wire resistance
20 ohm/wire (40 ohm total)
Maximum wire capacitance
60 nF
The wire resistance and capacitance typically corresponds to a 200 m wire.
RTD resistive
1,000 ohm
Range
500 to 2,200 ohm
  
Including wiring resistance
Accuracy
+/-(0.2 + 1.5 x 10 -3 x R) ohm
R = resistance in ohm
Resolution
0.1 ohm
RTD resistive wiring
Maximum wire capacitance
60 nF
Voltage outputs
Range
0 to 10 VDC
Accuracy
+/-60 mV
Resolution
10 mV
Minimum load resistance
5 kohm
Load range
-1 to +2 mA
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