Technical data

ManualsBrandsAllen-Bradley ManualsAdapter1794ASB Series B

Publication 1794-2.1 - January 2000

66 24V dc 8 Sink Input Module Cat. No. 1794-IB8 FLEX I/O and FLEX Integra Product Data

2-Wire and 3-Wire Inputs to the 1794-IB8

Module

Setting Input Filter Times

(Standard Mode Addressing Only)

You can select the input filter time (FT) for channels 00 through 07.

Select the input filter time by setting the corresponding bits in the

output image table (complementary word) for the module.

For example, to set a filter time constant of 4ms for a dc input module

at address rack 1, module group 0, set bits 02, 01, 00 as shown below.

Input Filter Times

Bits Description Selected Filter

Time

02 01 00 Filter Time for Inputs 00-07

0 0 0 Filter Time 0 (default) 256µs

0 0 1 Filter Time 1 512µs

0 1 0 Filter Time 2 1ms

0 1 1 Filter Time 3 2ms

1 0 0 Filter Time 4 4ms

1 0 1 Filter Time 5 8ms

1 1 0 Filter Time 6 16ms

1 1 1 Filter Time 7 32ms

01 0 1

0-15

16-33

34-51

2-Wire Device

(Sourcing Output)

2-Wire Row A and C

3-Wire Device

(Sourcing Output)

3-Wire Rows A, B,

and C

= Sink Input

= Common

= 24V dc

40876

40609

O:010

Write Filter Time on system startup.

FLL

Fill File

Source 4

Destination #O:010

Length 1

15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00

100

FT = 00-07

Write Filter Time Constant to complement of input module.

Dec.=4

Octal

or 4

Decimal

I:000

Specifications - 1794-IB8

Number of Inputs 8 non-isolated, sinking

Module Location Cat. No. 1794-TB3, -TB3S, or -TBN

Terminal Base Unit

ON-State Voltage 10V dc minimum;

24V dc nominal;

31.2V dc maximum

ON-State Current 2.0mA minimum;

8.0mA nominal at 24V dc;

11.0mA maximum

OFF-State Voltage 5.0V dc maximum

OFF-State Current 1.5mA minimum

Input Impedance 4.6K Ω maximum

Isolation Voltage 100% tested at 850V dc for 1s between user and

system

No isolation between individual channels

Maximum Input

Filter Times

OFF to ON

ON to OFF

256µs, 512µs, 1ms, 2ms, 4ms, 8ms, 16ms, 32ms

256µs default - selectable thru output image table

(see

Setting Input Filter Times

)

Flexbus Current (max) 20mA @ 5V dc

Power Dissipation Maximum 3.5W @ 31.2V dc

Thermal Dissipation Maximum 11.9 BTU/hr @ 31.2V dc

Indicators (field side

indication, customer

device driven)

8 yellow status indicators

Keyswitch Position 2

General Specifications

External dc Power

Supply Voltage

Voltage Range

24V dc nominal

19.2 to 31.2V dc (includes 5% ac ripple)

Dimensions HxWxD 46mm x 94mm x 53mm (1.8in x 3.7in x 2.1in)

Environmental Conditions

Operational Temperature

Storage Temperature

Relative Humidity

Shock Operating

Non-operating

Vibration

0 to 55

C (32 to 131

-40 to 85

C (-40 to 185

5 to 95% noncondensing

30g peak acceleration, 11(±1)ms pulse width

50g peak acceleration, 11(±1)ms pulse width

Tested 5g @ 10-500Hz per IEC 68-2-6

Conductors Wire Size