Rockwell Automation 1770, D17706.5.16 Ref Mnl DF1 Protocol Command - Manual (Page 229)

13–14 PLC Addressing
Publication 1770Ć6.5.16 - October 1996
Important: If the value of the mask or a level of the address is
greater than or equal to 255, then you cannot encode it
into 1 byte. You must flag this case by programming an
FF hex at the level address to signify that the level
address is greater than or equal to 255 and the next 2
bytes contain the level address. Then code the level
into the following two bytes.
The following figures show examples of PLC-5/250 logical binary
addresses.
PLCĆ5/250 Logical Binary Address to access the LP address 1N5:300
Byte
1
2
4
5
1 1 1 1 1 0 0
0 1 1 1 1 1 0 0
0 0 0 0 0 0 0 0
0 0 0 0 0 1 0 0
3 0 0 0 0 1 0 0 0
6 0 0 0 1 0 1 0 0
7 1 1 1 1 1 1 1 1
8 1 0 1 1 0 0 0 0
9 0 0 0 0 0 1 0 0
Byte 8 + Byte 9 = 300
mask byte: indicates the module ID byte and 5 levels of
addressing will be encoded.
1
level 1 (value = 2)
level 2 (value = 0)
level 3 (value = 1)
module ID byte (LP) = (class x 10) + pushweel (value = 31)
level 4 (value = 5)
level 5 flag (value = FF hex)
(44 - lower byte of word)
(256 - upper byte of word)
PLCĆ5 Logical Binary Address to access the RS address I:007
1
2
4
0 0 0 1 1 1 0 0
0 0 0 0 0 1 0 0
level 2 (value = 1)
0 0 0 1 1 1 0 0 level 3 (value = 7)
3 0 0 0 0 0 1 0 0
level 1 (value = 1)
Byte
mask byte; indicates 3 levels in the address
PLCĆ5/250 Logical Binary Address to access the LP address 2F0:0
1
2
4
5
1 0 1 0 1 1 0 0
1 0 0 0 0 0 0 0
level 1 (value = 2)
0 0 0 1 0 0 0 0
level 5 (value = 0, the default, but must be 0 0 0 0 0 1 0 0
level 3 (value = 4)
3 0 0 0 0 1 0 0 0
encoded because it is the last level)
Byte mask byte; indicates the module ID byte will be encoded
and there are 5 levels in the address. Levels 2 and 4 use
the default (0). Therefore, only levels 1,3, and 5 will be enĆ
coded. Even though level 5 is a 0, it must be encoded, beĆ
cause it is the last level in the address.
module ID byte (LP) = (class x 10) + pushwheel (value = 32)