General Purpose Inputs IN1 to IN4 Electrical Specifications

There are 4 identical general purpose digital inputs on the I/O connector. Each port exposes two pins named INxx-A and INxx-B respectively, where xx is a number ranging from 1 to 4.

This digital non-isolated differential input is polarity insensitive. Following type of devices are accepted:

The I/O controller measures the differential voltage and the differential impedance across both pins of each port sequentially. Therefore, it stimulates the external devices by applying alternatively positive and negative stimulation voltage Vs, as shown on the following diagram.

V16H264ProfessionalInputsCircuit

Professional Inputs 1-16 circuit

The impedance threshold is not adjustable. The voltage threshold is selectable among three values to determine the logic level of TTL, 5V CMOS, or 12V signals.

Hint. When you connect a low-impedance digital source (for instance a TTL gate), the capability to detect an open state can be used to detect a broken line.

Absolute max ratings

Parameter

Symbol

Min

Typ.

Max

Units

Absolute max voltage

VaAbsMax, VbAbsMax

 

 

25

V

Absolute min voltage

VaAbsMin, VbAbsMin

-25

 

 

V

The port does not operate correctly over the specified range. For normal operating conditions, refer to the DC characteristics table below.

The specification applies for both on and off power conditions.

DC characteristics

Parameter

Test condition(*)

Symbol

Min

Typ.

Max

Units

AC stimulation voltage

 

|Vs|

 

1.67

 

Vptp

DC bias voltage

 

Vbias

 

2.5

 

V

Input voltage range

"Logic input" operation

Varange,Vbrange

-7.8

 

12.8

V

Input current

 

Va (or Vb) = -5.0 V

Ia (or Ib)

 

1,32

 

mA

Va (or Vb) = -0.0 V

 

0,44

 

mA

Va (or Vb) = 2.5 V

 

0,00

 

mA

Va (or Vb) = 5.0 V

 

-0,44

 

mA

Va (or Vb) = 12.0 V

 

-1,67

 

mA

TTL Logic input operation (3V p.t.p signal)

Differential voltage threshold

Va in Vb within input voltage range

VTTLth

 

1.5

 

V

Common-mode voltage(**)

VTTLcmv

-6.3

1.5(***)

11.3

V

5V CMOS logic input operation (5V p.p. signal)

Differential voltage threshold

Va in Vb within input voltage range

VCMOSth

 

2.5

 

V

Common-mode voltage(**)

VCMOScmv

-5.3

2.5(***)

10.3

V

12V logic input operation (12V p.t.p signal)

Differential voltage threshold

Va in Vb within input voltage range

V12Vth

 

6

 

V

Common-mode voltage(**)

V12Vcmv

-1.8

6(***)

6.8

V

Contact operation - both pins floating

Differential impedance threshold

Potential-free contact

RPFth

 

5

 

Common-mode voltage(**)

VPFcmv

 

2.5

 

V

Contact operation - one pin at fixed potential

Differential impedance threshold

 

RFxth

 

8.5

 

Common-mode voltage(****)

VFXcmv

-7.8

 

12.8

V

(*) T = 25 °C, unless specified.

(**) Common-mode voltage = (Va + Vb)/2.

(***) One pin at GND.

(****) Common-mode voltage = voltage Va (or Vb) of pin at fixed potential.

AC characteristics

Parameter

Test condition(*)

Symbol

Value

Units

Sampling rate

 

f

200

Hz

Deglitching filter tap count(**)

Filter setting at 10 ms

tc

2

Samples

Filter setting at 100 ms

20

Samples

Minimum pulse width(***)

Filter setting at 10 ms

pwMin

35

ms

Filter setting at 100 ms

115

ms

(*) Tamb = 25°C, unless otherwise specified.

(**) 'tc' is the number of taps of the deglitching filter. The deglitching filter removes all transient input states having a number of consecutive identical samples smaller or equal to the value tc.

(***) This indicates the smallest pulse that the input lines can safely detect. This minimal value cannot be guaranteed in all circumstances; however, it can serve as guide lines for the system design.