1 1 / 0 0
IO-AI4-AO2
I / O E x p a n s i o n M o d u l e
Unitronics Industrial Automation Systems
7
Notes:
1. Note that the range of each I/O is defined both by wiring and within the controller’s software.
2. The analog value of an input may also indicate when the input is functioning out of range. If an analog
input exceeds the permissible range, its value will be 409
6
.
3. When an output that is delivering positive output voltage is connected to a load that short-circuits, the
SHORT CIRCUIT LED lights up on the module. The short circuit is also identified by the software
program within the controller connected to the module.
Within the M90 OPLC, for example, SB 5 turns ON. SI 5 contains a bitmap indicating the module
containing the affected output.
For more information, refer to the on-line help supplied with the programming package of your controller.
Addressing I/Os on M90 Expansion Modules
Inputs and outputs located on I/O expansion modules that are connected into an M90 OPLC are assigned
addresses that comprise a letter and a number. The letter indicates whether the I/O is an input (I) or an
output (O). The number indicates the I/O’s location in the system. This number relates to both the position
of the expansion module in the system, and to the position of the I/O on that module.
Expansion modules are numbered from 0-7 as shown in the figure below.
0
1
2
3
4
5
6
7
Expansion module
identification number
Adapter
The formula below is used to assign addresses for I/O modules used in conjunction with the M90 OPLC.
X is the number representing a specific module’s location (0-7). Y is the number of the input or output on
that specific module (0-15).
The number that represents the I/O’s location is equal to:
32 + x • 16 + y
Examples
Input #3, located on expansion module #2 in the system, will be addressed as I 67,
67 = 32 + 2 • 16 + 3
Output #4, located on expansion module #3 in the system, will be addressed as O 84,
84 = 32 + 3 • 16 + 4.
EX90-DI8-RO8 is a stand-alone I/O module. Even if it is the only module in the configuration, the EX90-DI8-
RO8 is always assigned the number 7.
Its I/Os are addressed accordingly.
Example
Input #5, located on an EX90-DI8-RO8 connected to an M90 OPLC will be addressed
as I 149, 149 = 32 + 7 • 16 + 5
