Omron SYSMAC CJ1W-PRM21, Operation Manual

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26
Unit Components
Section 2-1
2-1-3 Switch Settings
Setting the Unit Number The unit number is used to identify individual CPU Bus Units when more than
one CPU Bus Unit is mounted to the same PLC. The unit number must be
unique for each CPU Bus Unit. Selecting a non-unique number for a CPU Bus
Unit will prevent the PLC System from starting correctly.
1. Turn OFF the power supply before setting the Unit number.
2. Set the switch to the new Unit number. Use a small screwdriver to make
the setting, taking care not to damage the rotary switch. The unit number
is factory-set to 0.
3. Turn ON the power again.
Note Always turn OFF the power to the PLC CPU before changing the Unit number
setting. The Unit only reads the Unit number setting during the initialization
following a power-up, but not following a software reset.
Note If the unit number is being set for the first time or changed, then an I/O table
must be created for the PLC.
Unit Number and CPU Bus
Unit Word Allocations With CS/CJ-series PLCs, words are automatically allocated in the CIO Area
and the DM Area. The PROFIBUS-DP Master Unit uses these words for
receiving control data from the CPU Unit and for notifying the CPU Unit of
PROFIBUS-DP Master Unit and communications status. The word addresses
in the allocated areas for the CPU Bus Unit are important when creating the
user program for using the PROFIBUS-DP Master Unit. This must be consid-
ered when setting the unit number.
The CIO and DM Word allocations are discussed in detail in
4-2 Allocated
CIO Area Words
. The tables below show the relation between the unit num-
ber and the allocated CIO Area and DM Area words.
UNIT
No.
FE
DCB
A9876
543
210
CS1W-PRM21
NO.
UNIT
01
23
4567
89
AB
CDE
F
CJ1W-PRM21
Setting range:
0 ~ F (Hexadecimal)
Unit No.
(decimal)
Allocated words Unit No.
(decimal)
Allocated words
0 (0) CIO1500 to CIO1524 8 (8) CIO1700 to CIO1724
1 (1) CIO1525 to CIO1549 9 (9) CIO1725 to CIO1749
2 (2) CIO1550 to CIO1574 A (10) CIO1750 to CIO1774
3 (3) CIO1575 to CIO1599 B (11) CIO1775 to CIO1799
4 (4) CIO1600 to CIO1624 C (12) CIO1800 to CIO1824
5 (5) CIO1625 to CIO1649 D (13) CIO1825 to CIO1849
6 (6) CIO1650 to CIO1674 E (14) CIO1850 to CIO1874
7 (7) CIO1675 to CIO1699 F (15) CIO1875 to CIO1899