Omron CJ Series User Manual

1-11
1 Features and System Configuration
CJ-series PROFIBUS Master Unit Operation Manual for NJ-series CPU Unit (W509)
1-2 PROFIBUS Master Unit
1
1-2-1 PROFIBUS Master Unit Features
1-2 PROFIBUS Master Unit
 PROFIBUS Master Unit
The PROFIBUS Master Unit is a CPU Bus Unit, which can be installed on an NJ-series Controller
system.
 CPU Bus Unit
A total of up to 16 CPU Bus Units can be mounted on the CPU Rack or an Expansion Rack. The
total of 16 must include all PROFIBUS Master Units and all other CPU Bus Units.
 Unit Control and Status
Up to 25 words of control and status words are exchanged between the PROFIBUS Master Unit and
a dedicated CIO memory area, of which can be accessed by Device Variables (see 4-1-1 Data
Flow). Control bits allow the Controller program to switch the Unit between OFFLINE, STOP,
CLEAR and OPERATE mode, which represent the main PROFIBUS DP modes of operation. The
control words also allow for user initiated transmission of a Global-Control command over the PRO-
FIBUS network to any group of slave devices.
The remaining CIO words provide status and diagnostics information on the Unit itself, the PROFI-
BUS network and the slave devices.
 I/O Data
The total size of I/O data however, must not exceed the maximum I/O size of up to 7168 words,
which it can exchange with the Controller memory. The I/O data can be distributed over up to two
input areas and two output areas. Each of the input and output areas can be mapped to any location
in the DM Area, CIO Area, WR Area, HR Area, or the EM banks, of which can be accessed with
user-defined variables (see 4-1-1 Data Flow).
 PROFIBUS DP Class 1 Services
The PROFIBUS Master Unit supports all mandatory Class 1 services defined in the PROFIBUS DP
standard EN50170, Volume 2 for Master - Slave Communication. These functions includes the fol-
lowing services:
• Set_Prm
• Chk_Cfg
• Slave_Diag
• Data_Exchange
• Global-Control (FREEZE, UNFREEZE, SYNC, UNSYNC, CLEAR)
The PROFIBUS Master Unit supports cyclic Master - Slave communications for networks with up to
125 slave devices. With each slave device it can exchange up to 244 bytes of input data and up to
244 bytes of output data.
For diagnostics purposes the PROFIBUS Master Unit collects all Slave Diagnostics messages,
which it can transfer to the CPU memory, using commands. From every allocated slave device it can
receive up to 244 bytes of diagnostics data.
1-2-1 PROFIBUS Master Unit Features

Omron CJ Series Specifications

General

Brand	Omron
Model	CJ Series
Category	Controller
Language	English