46
(b) Precautions
• If I/O modules are mounted exceeding the maximum number, "SP.UNIT LAY ERR" (error code: 2124)
occurs.
• "Number of CPU modules" indicates the number set in "No. of PLC" of PLC parameter ("Multiple CPU
Setting").
• A C Controller module (Q24DHCCPU-V) occupies three slots. When this module is used, the maximum
number of mountable I/O modules will be two smaller than the number defined in the table on Page 45,
Section 3.2.1 (4) (a).
• When a C Controller module which occupies three slots is used, the maximum number of mountable I/O
modules will be two smaller than the number defined in the table on Page 45, Section 3.2.1 (4) (a).