Rockwell Automation 1797-OB4D FLEX Ex 24V DC Nonisolated Source 4 Output Module User Manual

Page 13

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FLEX Ex I/O 24V DC 4 Non-Isolated Source Output Module 13

Publication

1797-5.6 - June 2011

Overload Alarm

0 = No fault

1 = Output channel overloaded

(Load resistance range 30…5000

Ω)

100 Hz (10 ms) filter is integrated

Data

Output data

0 = Off

1 = On

Default = 0

Fault State

0 = Output goes to 0 during fault

1 = Hold last state

Default = 0

Detect Alarms

These bits can be used to activate/deactivate wire-off detection and
overload monitoring of the outputs for each channel.


0 = Wire-off detection/overload monitoring deactivated

1 = Wire-off detection/overload monitoring activated

Note: Leakage current will be present when output is at 0 state if Wire Off
detection is activated. The normal load range is defined as 30

Ω

…5 k

Ω. In

this range, no faults will occur. Wire off is assured to be reported for loads
> 75 k

Ω. It does not matter if the output is OFF or ON.

Latch Alarms

This bit defines for all channels, whether, in the event of a wire off or overload
fault, the corresponding fault bit (Overload Alarm, Fault Alarm) remains set
until the Reset Alarms bit in the configuration data word is reset by the user.
This ensures that a fault message is sent to the control system in the event of
a fault that is short in duration. The alarms should be latched if the Latch
Alarms bit is 1 and the outputs go to 0 state until the Reset Alarm occurs.

0 = Alarms and outputs are automatically reset

1 = Alarms and outputs are blocked and must be reset by setting the bit
Reset Alarms through the user program.

Default = 0

Outputs Enable

0 = Outputs disabled

1 = Outputs enabled

Default = 0

This bit must be set to 1 by the program for normal operation of the
outputs. When set to 0 the outputs will follow the Fault State status.

Field Descriptions

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