ProSoft Technology MVI69-103M - Manual (Page 82)

MVI69-103M ♦ CompactLogix or MicroLogix Platform Reference
IEC 60870-5-103 Master Communication Module
Page 82 of 131 ProSoft Technology, Inc.
November 3, 2008
Read Register Start = 0
Read Register Count = 120
Write Register Start = 200
Write Register Count = 120
Each area is broken down into blocks of 60 words. Therefore, the Read Register
Count and Write Register Count parameters should be multiples of 60.
The Read Data Area will be transferred from the module to the CompactLogix or
MicroLogix processor. The Write Data Area will be transferred from the
CompactLogix or MicroLogix processor to the module.
The following example shows the resulting data flow:
Command Control Blocks
Block identification codes greater than 9900 are utilized to perform special
functions in the module. Each control block recognized and used by the module
is defined in the following topics.
User Constructed Command Block (9901)
Block identification code 9901 issues one or more user constructed commands.
When the module receives a block 9901 identification code, it will place the
included commands into the command queue.
Word Offset in
Block Data Field(s) Description
0 Block ID This field contains the block identification code of 9901
for the block.
1 Command Count This field defines the number of user commands
contained in the block. The valid range for the field is 1
to 10.