Rockwell Automation 1791-XXXX ANALOG BLOCK I/O - Manual (Page 33)

Installing Block I/O
Chapter 2
2-15
Certain products are not compatible with extended node capabilities
obtained with the use of 82 ohm terminators. Table 2.G lists those products
that are not compatible.
Table 2.G
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
Block throughput using analog block is dependent on the controllers data
transfer rate. Analog block outputs are updated within 10ms of receiving
output data from the controller. The analog block inputs are sampled in a
“round robin” fashion with an input channel sampled every 27ms. This
means that a given input channel is sampled every 108ms (four input
channels times 27ms). At the end of every sample period of 27ms, the most
recent input data is made available for data transfer to the controller.
Consult your programmable controller user manual for Remote I/O
Communications to determine your system throughput.
Compatibility of 1771 I/O
Products with Extended
Node Numbers
Selecting Remote I/O
Link Speed