GE 8103-AI-TX 8-channel AI, 4-20mA
GENERAL
DI modules can accept up to 8, 16, or 32
discrete inputs, depending upon module
type, from dry contacts, NAMUR standard
proximity detectors, or switched voltages.
The source voltage for field switching can
be provided through the module or from an
independent supply out in the field.
In operation, the input voltage is compared
against a threshold voltage to create a ‘true’
or ‘false’ condition. If the inputs are from Zone
2/ Zone 1 or Zone 0 hazardous areas, the
appropriate (2/1) module provides certified
isolation for these signals. A pulse counter is
also included which can count the number of
input pulses for each of the channels.
Input filter
An input filter can be set individually for each
channel to introduce a delay period that
allows the input to settle to a stable value.
When switched off, the bandwidth of the DI
input is 250 Hz (100 Hz for 2/1 modules). The
timeout filter can introduce a timeout delay
of between 2 and 512 ms in 2 ms steps for
2/2 modules and between 3 and 512 ms in
3 ms steps for 2/1 modules. Alternatively,
preset values of “Fast” (22 ms) or “Slow”
(258 ms) may be used.
Latch
Any channel input can be configured to be
“real time” or latched. If the latch feature is
enabled, the polarity can also be set so that
an input signal that goes:
• High will be held high
• Low will be held low
until the latch is released by a command from
the controller. All channels are latched independently and can be cleared simultaneously,
or independently, by a Write instruction to the
module’s latch reset register. If controlled by
a BIM (rather than a Controller) this will occur
automatically in 2 to 3 seconds.
Line fault detection (2/1 only)
When enabled, this will cause a flag to be set
to indicate a short or open circuit fault.
Low-frequency pulse
Counter The DI modules contain a continuously running 16-bit pulse counter that
counts each low-frequency pulse received
on the input. The maximum pulse rate, with
the timeout filter switched off, depends upon
the module selected; consult the individual
data sheets for details. With the filter active,
the maximum pulse rate will be determined
by the timeout period used. In order to start a
particular count the counter must be reset to
zero by a host instruction. When the counter
overflows (i.e. > 65,536 counts) it will restart
from zero.

MODULE OPERATING STATES
“Failsafe” mode
The module supports failsafe mode as defined
in the earlier I/O module introductory section.
Channel Active/Inactive
Each channel can be made active or inactive
individually. When a channel is made inactive:
• Inputs are not processed—i.e. the last input
value is held and not refreshed
• Channel events are not generated
• The counter is not incremented
Power-up conditions
On power-up, or if a reset is executed, the
configuration will automatically adopt
predefined states:
Module mode:
Normal (not “failsafe”)
Channel types:
All latches and filters are off
Active/Inactive:
All channels power-up in the Active state
Visual indicators
On Channel input “high” or latched
Off Channel input “low”
Flashing Line fault detect (2/1 only)
Channel “Status” LED (yellow)
On the DI modules the yellow “Status” LED
reacts in the following way to module conditions.
NOTE: The LED may appear to flash when the input goes
high and low repeatedly