152
IR Area
Section 3-2
Note
1.
I/O words are not allocated to the I/O Control Unit or I/O Interface Unit.
2.
I/O words are not allocated to the Analog Power Supply Unit, but it is count-
ed as one of the mounted Units.
I/O Capacity and
Requirements
The number of I/O bits that can be allocated depends on the CQM1H CPU
Unit being used, as shown in the following table. Be sure to take into account
the one input word (IR 000) that is automatically allocated to inputs on the
CPU Unit. If the number of words allocated exceeds the capacity of the CPU
Unit, a fatal I/O UNIT OVER error (error code E1) will occur.
Refer to page 153 for a table showing how many I/O words are required by
each I/O Unit and page 154 for a table showing how many I/O words are
required by each Dedicated I/O Unit.
AR 22 indicates the number of input words and output words that have been
allocated, as shown in the following diagram.
The CQM1H does not have a Backplane, so it isn’t necessary to deal with
empty slots when allocating I/O words. The lowest available I/O word
addresses are allocated automatically.
Inputs are automatically allocated to input words and outputs are automati-
cally allocated to output words regardless of the order in which the Input Units
and Output Units are mounted. Even though I/O allocation is not affected, it is
recommended that the Input Units be mounted together and Output Units be
mounted together to make the word allocation easier to understand and help
eliminate problems with noise.
CPU Unit
Max. number of I/O bits
Number of I/O words available to
Units other than the CPU Unit
CQM1H-CPU61 512 bits (256 inputs and
256 outputs)
(32 words: 16 input and
16 output words)
31 (15 input words, 16 output words)
CQM1H-CPU51
CQM1H-CPU21 256 bits
15
CQM1H-CPU11
Word
Bits
Function
Data range
AR 22
00 to 07 The number of input words that
have been allocated.
01 to 16 (2-digit BCD)
08 to 15 The number of output words
that have been allocated.
00 to 16 (2-digit BCD)
