ProSoft Technology inRax MVI69-101M User Manual page 82

MVI69-101M ♦ CompactLogix or MicroLogix Platform
IEC 60870-5-101 Master Communication Module
After the module has received the configuration, the module will begin receiving
and transmitting messages with devices on the serial networks.
Main Logic Loop
Upon completing the power up configuration process, the module enters an
infinite loop that performs the following functions:
Backplane Data Transfer
The MVI69-101M module communicates directly over the CompactLogix or
MicroLogix backplane. Data is paged between the module and the processor
across the backplane using the module's input and output images. The frequency
of update of the images is determined by the scheduled scan rate defined by the
user for the module and the communication load on the module. Typical updates
are in the range of 2.5 to 10 milliseconds.
This bi-directional transference of data is accomplished by the module filling in
data in the module's input image to send to the processor. Data in the input
image is placed in the Controller Tags in the processor by the ladder logic. The
input image for the module is user configurable. This large data area permits fast
throughput of data between the module and the processor.
The processor inserts data to the module's output image to transfer to the
module. The module's program extracts the data and places it in the module's
internal database. The output image for the module is user configurable. This
large data area permits fast throughput of data from the processor to the module.
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From Power Up Logic
Call I/O Handler
Rx and Tx buffer routines are interrupt driven. Call to
Call CFG/DEBUG Port
Driver
Call Network Master
Drivers
Call I/O Handler
Transfers data between the module and processor
(user, status, etc.)
Call Serial Port Driver
serial port routines check to see if there is any data
in the buffer, and depending on the value, will either
service the buffer or wait for more characters.
Call Network Master Drivers
Generate Messages.
Reference
ProSoft Technology, Inc.
February 4, 2008