![background image](http://html1.mh-extra.com/html/omron/cj1w-prt21/cj1w-prt21_operation-manual_742353059.webp)
2-3
2 Nomenclature and Installation
CJ-series PROFIBUS Slave Unit Operation Manual for NJ-series CPU Unit (W510)
2
-1 Un
it Co
mp
on
ent
s
2
2-
1-3 Sw
itch Settings
The CJ1W-PRT21 has 4 rotary switches to
•
set its Special I/O Unit number or Machine No. (00-95)
•
set the PROFIBUS-DP node address (00-99)
Precautions for Safe Use
Always turn off the power to the CPU before changing a rotary switch setting.
The Unit only reads the settings during the initialization after power-on. Use a small flat-blade screw-
driver to turn the rotary switches; be careful not to damage the switches.
Machine Number
The MACH No. rotary switches are used to select the CJ1 Special I/O Unit number or so called
“Machine No.”.
The Special I/O number setting determines which words in the CIO Area and Data Memory Area are
allocated to the CJ1W-PRT21 (see
).
Any Machine number in the setting range is allowed as long as it has not been set on another Spe-
cial I/O Unit connected to the CPU. If the same number is used for the CJ1W-PRT21 and another
Special I/O Unit, an error will occur in the CPU and it will not be possible to start up the PROFIBUS-
DP Slave communication (see
A-1-2 Differences in Access Methods from a User Program
).
Node Address
Two switches, marked Node No. x10
1
and x10
0
, are used to set the PROFIBUS-DP node address
of the Unit. Addresses in the range of 00 through 99 are valid. Be sure the node address on the unit
is equal to the station address in the PROFIBUS master configuration.
2-1-3
Switch Settings