1-3
Section
System Configuration
7
1-3
System Configuration
A CompoBus/D (DeviceNet) system can be constructed in two ways: fixed al-
location or free allocation.
A DeviceNet system can be constructed easily even without the Configurator.
With fixed allocation, predetermined words are allocated to each node for the
Slave’s I/O.
An OMRON Master Unit must be used in order to perform fixed allocation. More-
over, with fixed allocation only one Master Unit can be used in a DeviceNet net-
work and only one Master Unit may be mounted to a PC.
The Configurator can be used to freely allocate the words used by each Slave.
With free allocation, more than one Master Unit can be connected in a Device-
Net network and each Master’s Slave I/O can be set independently. More than
one Master Unit may be mounted to each PC and those Masters can be used
independently. Furthermore, other companies’ Masters can be used.
Reference 1. The maximum number of words occupied by the DeviceNet Interface Unit is
32 input words and 32 output words. The number of input words and output
words can be set independently from 0 to 32 words. Do not allocate words
that are allocated to another Slave.
2. The maximum number of points controlled by each Master is lower with
fixed allocation than it is with free allocation. When the DeviceNet Interface
Unit is allocated a large number of words, do not exceed the maximum num-
ber of points that can be controlled by the Master. In particular, if a C200HS
is used as the Master with fixed allocation, the DeviceNet Interface Unit will
use all of the available points (32 input words and 32 output words) and it
won’t be possible to connect another Slave.
3. Each Master Unit and Configurator is connected as a single node in the De-
viceNet network and requires a unique node number.
1-3-1 Master Units
The following OMRON Master Units are available.
Applicable PC
Master Unit model
Mounting position
Max. number of Units
number
With
Configurator
Without
Configurator
CVM1, CV Series
CVM1-DRM21-V1
CPU or Expansion CPU Rack
(Classified as CPU Bus Units)
16
1
CS1 Series
C200HW-DRM21-V1
CPU Rack or Expansion I/O Rack
16
C200HZ/HX/HG/HE
(Classified as Special I/O Units)
10 or 16
(see note)
C200HS
10
Note Some CPUs can control 16 Master Units and other CPUs can control 10.
Fixed Allocation
Free Allocation
