ProSoft Technology MVI56-DFCM - Manual (Page 73)

MVI56-DFCM ♦ ControlLogix Platform Reference
DF1 Half/Full Duplex Master/Slave Serial Communication Module User Manual
ProSoft Technology, Inc. Page 73 of 106
September 24, 2014
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.
The following illustration shows the data transfer method used to move data
between the ControlLogix processor, the MVI56-DFCM module and the DF1
network.