Rockwell Automation 1771-ASB/E Remote I/O Adapter User Manual - Manual (Page 28)

2–14 Installing Your Module
Publication 1771-UM001A-US-P - February 2000
If this is the last remote I/O adapter on the link, you must use a
terminating resistor to terminate both ends of the remote I/O link
(scanner end and last adapter end). Connect the terminator across
terminals 1 (blue) and 3 (clear).
The size of the terminator is determined by the system configuration.
Older configurations use a 150 ohm resistor at both ends. With newer
products that can support it, you can use an 82 ohm terminator at
both ends. The 82 ohm terminators provide “extended node”
capability which allows you to have up to 32 physical devices on the
RIO link. (The number of logical racks capable of being addressed
by the scanner is not affected.) This allows 1/4, 1/2 and 3/4 racks,
Dataliners, Redipanels and Panelview devices to be attached to the
link.
!
ATTENTION: Devices that are operating at 230.4K
Baud must have 82 ohm terminators in place for proper
operation.
Certain products are not compatible with the extended node
capabilities obtained with the use of the 82 ohm terminator resistors.
These products are listed below.
Table 2.E
NonĆcompatible Products
Device Series
Scanners Ć 1771ĆSN All
1771ĆSD All
1772ĆSD2 All
1775ĆSR All
1775ĆS4A All
1775ĆS4B All
Adapters Ć 1771ĆAS All
1771ĆASB Series A
1771ĆDCM All
Miscellaneous Ć 1771ĆAF All
1771ĆAF1 All
Installing the Terminator
Compatibility of 1771
Remote I/O Productswith
Extended Node Numbers