Eaton easy800

5 Function blocks
5.3 BC, data block comparator
146 Control Relay easy800 11/11 MN04902001Z-EN www.eaton.com
Example 2:
Comparison of marker blocks, definition of a marker range with offset
Two marker blocks are to be compared. Block 1 starts at MB15, Block 2
starts at MB65. Each block is 4 bytes long.
• Parameters of function block BC01:
The comparison result of the function block BC01 is: BC01EQ = 0, the data
block ranges do not have the same content. MB18 and MB68 are not
identical.
Example 3:
Comparison of marker blocks, definition of a marker range in a different
format
Two marker blocks are to be compared. Block 1 starts at MB60,
Block 2 starts at MD80. Each block is 6 bytes long.
• Parameters of function block BC01:
• Comparison range 1: I1 MB15
• Comparison range 2: I2 64
• Number of bytes: NO 4
• Marker MB01: 1
￫
Comparison range 2: Constant 64:
MB01 plus offset: 1 + 64 = 65  MB65.
Comparison range 1
Value of marker range
1 (decimal)
Comparison range 2 Value of marker range
2 (decimal)
MB15 45 MB65 45
MB16
62 MB66 62
MB17
102 MB67 102
MB18
65 MB68 57
• Comparison range 1: I1 MB60
• Comparison range 2: I2 MD80
• Number of bytes: NO 6
￫
The comparison is in byte format. MD80 has 4 bytes.
Therefore the first two bytes of MD81 are also compared.