ProSoft Technology 5210-DFNT-RIO - Manual (Page 8)

RIO ♦ ProLinx Gateway Protocol Functional Overview
Rockwell Automation® Remote I/O Adapter Driver Manual
Page 8 of 39
ProSoft Technology, Inc.
February 4, 2010
The internal database is central to the functionality of the module. This database
is shared between all the ports on the module and is used as a conduit to pass
information from one device on one network to one or more devices on another
network. This permits data from devices on one communication port to be viewed
and controlled by devices on another port.
In addition to data from the slave and master ports, status and error information
generated by the module can also be mapped into the internal database.
1.2.1 Remote I/O Access to Database
This same internal database is used by the RIO interface to pass information
between the module and the RIO scanner.
A RIO scanner attached to the module can request data from the module’s
database using BTR commands. BTW commands transfer data from the RIO
scanning device to the module’s database. Each data-block is capable of
transferring up to 60-words of data in each block. The module sequentially steps
through the list of read and write blocks configured in the module to transfer the
data between the module and the RIO scanner. The following illustration shows
these relationships:
Master
Driver
Logic
Slave
Driver
Logic
Module’s
Internal
Database
4601-RIO-MCM Module
To Modbus
Master
Device
Ladder logic
transfers
data from
module using
BTR commands
Processor
Ladder logic
transfers
data to
module using
BTW commands
Input Image
BTW Blocks
RI
O
I
n
te
rf
a
c
e
Input Image
Read Data
Write Data
Output Image
BTR Blocks
Output image
To Modbus
Slave
Devices
In addition to the block transfer operations, the module reports high-speed data to the RIO scanner
through the input and output image table. The size of this table depends on the rack size selected.
The following table defines the input/output word count for the different rack size selections:
Rack Size Input Word Count Output Word Count
1/4 Rack 1 1
1/2 Rack 3 3
3/4 Rack 5 5
Full Rack 7 7