Toshiba T2N - Manual (Page 210)

User's manual 197
4. I/O Allocation
4.4
Register and Module
Correspondence
When input/output allocation information is registered by carrying out
automatic allocation or individual allocation, equivalence between
registersnand modules is automatically determined by the following rules.
(1) In any unit, allocation is the low address registers are allocated in
sequence from the module at the left end.
(2) In a case when the unit leading address is not set (it is never set
by automatic allocation), the registers are allocated in continuation
from the previous stage unit.
(3) A slot for which a module type is not set (any vacant slot in
automatic allocation is the same) does not occupy any registers
(4) The cases of basic/expansion type rack except 8 slots I/O also
are handled in the same way as standard size rack (8 slots) for
input/ output allocation,and they are regarded as having slots
without settings in the latter portions of the unit. Therefore these
portions do not occupy registers.
(5) Slots for which SP (space) is set, output registers are allocated
internally by a number of set words.
(6) Modules for which Z, OPT, TL-S and TL-F are set do not occupy
input/output registers (XW/YW).
(7) t/output registers which are not allocated to I/O modules become
output registers (YW) in the programming. Thus, they can be
used in the same way as auxiliary registers/relays (RW/R).
For the allocation of link registers/link relays to data transmisson
modules, see the separate manual for these modules.
NOTE