Eaton Electrical D77A - Manual (Page 30)

Intelligent Technologies ( IT.) D77A I/O Module Products
22 For more information visit: www.EatonElectrical.com MN05002001E
Theory of Operation
The IT. D77A I/O system consists of a collection of input and output modules connected together by QCPort to a network adapter. The
network adapter connects to the industrial network where the controller usually is a PLC or DCS. The input modules collect digital or
linear signals from sensors (limit switches, proximity sensors, temperature transmitters, etc.) and deliver these data to the control
device. In the control device, input data values are placed in data registers. Based on the input data, the control algorithm manipulates
values in the output registers. With each scan of the network, the input and output data registers are updated. With this update, the
output modules have their digital or linear data changed to reflect the control algorithm found in the control device software. The
output devices (solenoid valves, motor starters, temperature gauges, etc.) effect changes to the machinery being controlled.
Out-of-box Default Operation
When the IT. D77A I/O modules are properly installed and each has a properly configured Group ID (address), no additional
configuration is needed for standard operation. To customize the configuration, refer to Configuration on page 34. After customizing
the configuration, the system can be restored to the default out-of-box configuration without a software tool such as CH Studio by
following these steps.
1. Using a screwdriver, rotate the Group ID Switch from the “0” position to the “1” position.
2. Repeat this action five times.
The status LED rapid flashes, signaling that the system is reset to the out-of-box default settings.
Typical Application
Figure 16 illustrates a typical D77A I/O module application this is integrated with a number of IT. starters with QSNAPs. In this
example, a D77A I/O is part of a larger system where motor control and I/O are required within a single panel. On the same QCPort
connection, both the I/O and the motor control are connected to a single network Adapter. The network adapter then represents the
D77A I/O and motor control as remote I/O, allowing for control and monitoring of the QCPort devices.
Figure 16: Panel Layout: Adapter, I/O and QSNAP
a) PC or PLC Connection
b) I/O Modules
c) QCPort Connection
d) IT. Starters with QSNAPs
e) Power Tap/Terminator Resistor
f) 24 V DC Power Supply
D77A-003
a
c
b
d
e
f