ProSoft Technology MVI56-103M - Manual (Page 59)

MVI56-103M ♦ ControlLogix Platform Ladder Logic
IEC 60870-5-103 Master Communication Module User Manual
ProSoft Technology, Inc. Page 59 of 152
February 22, 2013
Backplane Object (I103MBackplane)
The I103MBackplane object stores all the variables required for the data transfer
operation between the module and the controller. The LastRead data member is
used as the handshaking word to indicate the arrival of new data from the
module. The following table describes the structure of the object.
Name Data Type Description
LastRead INT
LastWrite INT
BlockIndex INT
The other members of the object are utilized in the ladder logic to assist in the
data transfer operation.
3.1.2 Data Object
Data for the module is stored in two controller tags for the example ladder logic.
The Read Data (data transferred from the module to the processor) is stored in
the controller tag array, I103ReadData[ ]. The Write Data (data transferred from
the processor to the module) is stored in the controller tag array, I103WriteData[
]. Separate tags can be constructed for each data type utilized by the controlled
devices and for each device.