ProSoft Technology MVI69-ADM - Manual (Page 33)

MVI-ADM ♦ 'C' Programmable Understanding the MVI-ADM API
'C' Programmable Application Development Module Developer's Guide
ProSoft Technology, Inc. Page 33 of 342
February 20, 2013
Ladder logic must process this block of information and place the data received
in the correct data files in the . The processor requests this block of information
using the following write block:
M1 Offset Description Length
7800 9997 1
Warm Boot Block (9998)
This block is sent from the SLC processor to the module when the module is
required to perform a warm-boot (software reset) operation. This block is
commonly sent to the module any time configuration data modifications are made
in the configuration data area. This will cause the module to read the new
configuration information and to restart. The following table describes the format
of the control block.
M1 Offset Description Length
7800 9998 1
Cold Boot Block (9999)
This block is sent from the SLC processor to the module when the module is
required to perform the cold boot (hardware reset) operation. This block is sent to
the module when a hardware problem is detected by the ladder logic that
requires a hardware reset. The following table describes the format of the control
block.
M1 Offset Description Length
7800 9999 1
MVI56 Backplane Data Transfer
The MVI56-ADM module communicates directly over the backplane. Data is
paged between the module and the ControlLogix processor across the backplane
using the module's input and output images. The update frequency of the images
is determined by the scheduled scan rate defined by the user for the module, and
by the communication load on the module. Typical updates are in the range of 2
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 set to 250 words. 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 set to 248 words. This
large data area permits fast throughput of data from the processor to the module.