Revised 7/10/01 • InterOP8500
10
© 2001 Automated Logic Corporation
Termination Row 3
This terminal is the
unswitched input signal common.
Termination Row 4
This terminal is not
used.
Termination Row 5
This terminal is the
switched input signal common and is
available only on AI points 8 through 15.
Unswitched and Switched Inputs
Unswitched inputs, the most common type of
input, reference the sensor to the module's
ground, the same ground referenced by all
other unswitched input sensors. This type of
input is for devices that are "floating,"
meaning that they are not ground referenced
anywhere. Examples would be RTD inputs or
dry contacts.
Switched inputs are selected one at a time,
and the circuit board's ground is then
referenced to the module's "Switched
Ground" lead. This feature allows modules
that are not floating, and that may have a
small amount of ground shift, to give stable
readings on their AIs. Examples would be 0-
5VDC or 0-2.5VDC devices.
NOTE
NOTE
NOTE
NOTE The channel number is not affected
by the input's condition (switched or
unswitched).
Table 3. Acceptable Analog Input Signals
Analog Input
Type
Power
Jumper?
Switched?
RTD -
thermistor
Internal
Yes
Unswitched
0-5VDC -
linear
Internal
No
Switched or
Unswitched
0-2.5VDC -
linear
Internal
No
Switched or
Unswitched
4-20mA -
linear
(Offset/Gain
setup as
1-5VDC)
External (plus
parallel 250
ohm resistor)
No
Unswitched
Figure 12. I/O Terminals for the Field Termination Board
B i n a ry In p u t s
B i n a ry C o m m o n
U n u s e d
+
-
1 2 V D C
In p u t fro m e x t e rn a l
+ 1 2 V D C P o w e r S u p p ly
1
2
3
4
5
6
7
8
9
1 0 1 1 1 2 1 3 1 4 1 5
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
3
5
5
5
5
6
6
6
7
7
8
8
A n a lo g In p u t s
+ 2 . 5 V D C
U n u s e d
S w it c h e d
C o m m o n
U n u s e d
B in a ry O u t p u t s
B i n a ry C o m m o n
A n a l o g In p u t s
+ 2 . 5 V D C
A n a l o g C o m m o n
(U n s w it c h e d )
U n u s e d
B I #
B O #
A I #
A n a l o g C o m m o n
(U n s w it c h e d )
