Yaskawa 120 Series I/O Modules - Manual (Page 115)

3.4 I/O Allocation
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3) I/O Reference Number Setting
(a) The leading I/O reference number used by the Input Module is set.
(b) Any one of the I/O reference numbers and points listed in the following table
can be set.
(c) When an input relay is set, the leading I/O reference number must satisfy the
following equation:
Leading reference number of I/O relay = 100001 + 16 n
where n = 0 to 63 for the CPU20 and
n = 0 to 255 for the CPU30
For example, 100001 can be set as the leading reference number, but
100002 cannot.
4) I/O Data Format
The following items can be set to define the I/O data format. There is, however, gen-
erally no need to change these settings because the default settings can be used
for most normal applications.
a) Bit Order
I/O can be processed by handling data either in ascending or descending order of
the bits. This is explained next for allocation of both input relays and input registers.
(1) When 32-point input relays are allocated from 100001, the bit order can be set
to either “MSB” or “LSB,” as described in the following table and shown in the
illustration below it. Allocation is performed in units of 16 input points.
Refer to Fig. 3.3 Allocation of Input Relays for details.
Type of Input References for I/O Allocation Points/Registers
CPU10, CPU20, CPU21 CPU30, CPU35
Input Relays 100001 to 101024 100001 to 104096 32 points
Input Registers 300001 to 300512 300001 to 300512 2 registers
Input Relay MSB Setting The leading input reference number (100001) is allocated to the
smallest input number of the first 16 input points (input 1) on the Input
Module. The next input reference number (100017) is allocated to the
smallest input number of the second 16 input points (input 17) on the
Input Module.
Input Relay LSB Setting The leading input reference number (100001) is allocated to the larg-
est input number of the first 16 input points (input 16) on the Input
Module. The next input reference number (100017) is allocated to the
largest input number of the second 16 input points (input 32) on the
Input Module.