ABB IMASI13, Instructions Manual

Page: 62 / 128

WBPEEUI240766B0 2 - 1
Section 2
Description and Operation
Introduction
This section explains the inputs, control logic, communication,
and connections for the IMASI13 module. The ASI module
interfaces 16 analog inputs to a Harmony controller. The Har-
mony controller communicates with its I/O modules over the
I/O expander bus (Fig.
1-1 ). Each I/O module on the bus has
a unique address set by its address dipswitch (S1).
Module Description
The ASI module consists of a single printed circuit board that
occupies one slot in a module mounting unit (MMU). Two cap-
tive latches on the module front panel secure it to the module
mounting unit.
The ASI module has three card edge connectors for external
signals and power: P1, P2 and P3. P1 connects to the supply
voltages. P2 connects the module to the I/O expander bus,
over which it communicates with the controller. Connector P3
carries the inputs from the termination cable plugged into the
termination unit (TU). The terminal blocks for field wiring are
on the termination unit.
A single dipswitch on the module sets its address or selects
onboard tests. Jumpers configure the type of analog input sig-
nals.
Functional Operation
The ASI module is an intelligent module with an onboard
microcontroller and memory. It interfaces to a controller over
the I/O expander bus. An onboard microcontroller allows the
ASI module to perform the input channel processing. This
allows the controller to do other tasks. Input processing tasks
include error compensation, adjustments, and conversion to
engineering units.