Rockwell Automation 1791-XXXX Discrete I/O AC and DC Block I/O Input and Output Modules - Manual (Page 57)

Installing Block I/O
Chapter 3
3-38
Certain products are not compatible with extended node capabilities
obtained with the use of 82 ohm terminators. Table 3.D lists those products
that are not compatible.
Table 3.D
NonĆcompatible Products
Device Series
Scanners Ć 1771ĆSN All
1772ĆSD All
1772ĆSD2 All
1775ĆSR All
1775ĆS4A All
1775ĆS4B All
Adapters Ć 1771ĆAS All
1771ĆASB Series A
1771ĆDCM All
Miscellaneous Ć 1771ĆAF All
1771ĆAF1 All
The remote I/O link can operate at three speeds: 57.6K, 115.2K or 230.4K
bits/s. The selection of link speed is dependent on the scanner/processor
used, throughput requirements, distance required and the type of remote
I/O devices being used.
Throughput Requirements
The throughput, a portion of which is I/O scan time, must be balanced
against the distance requirements for the application. The typical discrete
I/O scan time is shown in Table 3.E below. Use these values along with
your processor/scanner manual to determine system throughput.
Table 3.E
I/O Scan Time vs. Remote I/O Link Distance
57.6K Bits/s 115.2K Bits/s 230.4K Bits/s
Typical Discrete I/O Scan
Time (each block)
10ms 7.0ms 3ms
Remote I/O link distance 10,000 ft. 5,000 ft. 2,500 ft.
Compatibility of 1771 I/O
Products with Extended
Node Numbers
Selecting Remote I/O Link
Speed