Rockwell Automation 1747-ASB Remote I/O Adapter - Manual (Page 22)

Publication 1747-UM006B-EN-P - June 2003
1-8 Overview
Physical and Logical RIO Link Specifications
The maximum number of adapters that your scanner can
communicate with is determined by the scanner and adapter's
physical and logical specifications, as described below:
Physical Specifications are the maximum number of adapters that can
be connected to the scanner. For more information, see Extended
Node Capability below.
Logical Specifications for the scanner are the maximum number of
logical racks the scanner can address, how the logical racks can be
assigned, and whether the scanner can perform block transfers.
For adapters, logical specification refers to the maximum size of the
adapter's RIO image.
Extended Node Capability
Both scanners and adapters can have extended node capability.
Extended node capability allows you to use an 82 Ohm termination
resistor at both ends of the RIO link for all baud rates. Extended node
capability also allows for up to 32 adapters to be placed on the RIO
link.
Extended node capability can only be used if the scanner and all
adapters on the RIO link have extended node capability. The
1747-ASB module has extended node capability.
The tables on pages 1-10 and 1-11 provide lists of compatible RIO
scanners and adapters.
The 1747-ASB module is compatible with all Allen-Bradley scanners.
Scanners that do not support RIO block transfers do not work with all
of the I/O modules supported by the 1747-ASB module. For example,
the Catalog Number 1747-SN Series A, RIO Scanner does not work
with a Catalog Number 1746-BAS, BASIC module because the scanner
does not support RIO block transfer.