ProSoft Technology MVI56E-GSC/ GSCXT - Manual (Page 83)

MVI56E-GSC ♦ CompactLogix or MicroLogix Platform Reference
Enhanced Generic ASCII Serial Communication Module User Manual
ProSoft Technology, Inc. Page 83 of 140
May 9, 2014
Read-Write Devices
Read-write devices are those that both send and receive data. An example of
this type of device is a computer terminal. A terminal will send data entered on
the keyboard out its serial port and display any data received on its port on the
monitor.
All data received from the terminal keyboard will be routed to the ControlLogix
processor through the MVI56E-
GSC’s input image. Data to be written to the
terminal screen will be sent to the module using the output image. The module
will send new data from the output image out the application port to the terminal.
The example shipped with the module can be used to interface with a terminal to
echo back all characters received.
The data flow diagram for a read-write device is shown below: