32
Group-2 High-density I/O Units and B7A Interface Units are allocated words be-
tween IR 030 and IR 049 according to I/O number settings made on them and do
not use the words allocated to the slots in which they are mounted. For 32-point
Units, each Unit is allocated two words; for 64-point Units, each Unit is allocated
four words. The words allocated for each I/O number are in the following tables.
Any words or parts of words not used for I/O can be used as work words or bits in
programming.
32-point Units 64-point Units
I/O number Words I/O number Words
0IR 30 to IR 31 0IR 30 to IR 33
1IR 32 to IR 33 1IR 32 to IR 35
2IR 34 to IR 35 2IR 34 to IR 37
3IR 36 to IR 37 3IR 36 to IR 39
4IR 38 to IR 39 4IR 38 to IR 41
5IR 40 to IR 41 5IR 40 to IR 43
6IR 42 to IR 43 6IR 42 to IR 45
7IR 44 to IR 45 7IR 44 to IR 47
8IR 46 to IR 47 8IR 46 to IR 49
9IR 48 to IR 49 9Cannot be used.
AIR 330 to IR 331 AIR 330 to IR 333
BIR 332 to IR 333 BIR 332 to IR 335
CIR 334 to IR 335 CIR 334 to IR 337
DIR 336 to IR 337 DIR 336 to IR 339
EIR 338 to IR 339 EIR 338 to IR 341
FIR 340 to IR 341 FCannot be used.
When setting I/O numbers on the High-density I/O Units and B7A Interface
Units, be sure that the settings will not cause the same words to be allocated to
more than one Unit. For e x a m ple, if I/O number 0 is allocated to a 64-point Unit,
I/O number 1 cannot be used for any Unit in the system.
Group-2 High-density I/O Units and B7A Interface Units are not considered Spe-
cial I/O Units and do not affect the limit to the number of Special I/O Units allowed
in the System, regardless of the number used.
The words allocated to Group-2 High-density I/O Units correspond to the con-
nectors on the Units as shown in the following table.
Unit Word Connector/row
32-point Units mRow A
m + 1 Row B
64-point Units mCN1, row A
m + 1 CN1, row B
m + 2 CN2, row A
m + 3 CN2, row B
Note 1. Group-2 High-density I/O Units and B7A Interface Units cannot be mounted
to Slave Racks.
2. Refer to the Installation Guide for limitations on the number of Special I/O
Units that can be mounted to Slave Racks.
Allocation for Group-2
High-density I/O Units and
B7 Interface Units
IR (Internal Relay) Area Section 3-3