Scan List - Omron CJ1W-DRM21 Operation Manual

4-2

Scan List

4-2-1

Scan List

A scan list is used to register the slaves with which the Master Unit communicates in DeviceNet remote
I/O communications. It is the basis on which the Master Unit communicates with slaves.
The Master Unit does not contain a scan list by default. DeviceNet Unit, however, has a default setting
that allows it to communicate with all slaves even with the scan list disabled, but this operating mode
should not be used for normal operation. Always create a scan list prior to operating the Unit.
Scan List Contents
The contents of the scan list is listed in the following table. When a Master Unit goes online, it com-
pares each of these items with the slaves that are actually connected to the network. The items that
are compared, however, will depend on the allocation method that is used.
Item
Node address Node address for
every Slave
Allocated IN/OUT Settings of the num-
sizes and allocation ber of bytes allocated
to every slave in a
data area of the Mas-
ter Unit
Vendor Unique manufacturer
ID
Device type Unique product type
value
Product code Unique product model
value
Connection type Applicable DeviceNet
protocol
(See A-2 DeviceNet
Connections for
details.)
Connection path Type of slave I/O data
(See A-2 DeviceNet
Connections for
details.)
CJ-series DeviceNet Units Operation Manual for NJ-series CPU Unit(W497)
Description Fixed allocations
Compared
Compared
Not compared
Not compared
Not compared
Automatically set
Cannot be set
4 Remote I/O Master Communications
User-set allocations
using device vari-
ables for CJ-series
Unit
Compared
Compared
Set from CX-Integra-
tor
Set from CX-Integra-
tor
Set from CX-Integra-
tor
Automatically set or
set from CX-Integrator
Set from CX-Integra-
tor
User-set allocations
from the CX-Integra-
tor
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