Rockwell Automation 6008-SV2R VMEbus remote I/O Scanner - Manual (Page 16)

Chapter
Scanner Overview
1
1Ć8
Getting the Scanner's Attention
For a VME master processor to get the scanner’s attention, it must write a
value (any value) to any byte in the scanner’s identification area. This area
is located in the last 64 bytes of the global RAM for each scanner channel.
The scanner gets the attention of a VME master processor by generating a
VMEbus interrupt to which the VME master processor must respond. This
interrupt is sent when the scanner finishes commands that a VME master
processor initiated.
The 6008-SV1R and 6008-SV2R scanners replace and are backward
compatible with the Allen-Bradley 6008-SV VMEbus remote I/O scanner.
The 6008-SV1R and 6008-SV2R scanners offers these improvements:
each remote I/O channel controls as many as 32 adapters
configurable communication rate of 230.4, 115.2, or 57.6 kbps lets you
select I/O scan time
embedded communication microprocessor increases
scanner performance
VME interrupt signals change in the scanner input table
configurable VME operating mode lets you select the scanner features
you need for your application
Important: The SCAN LIST command is the only difference between the
6008-SV1R and 6008-SV2R scanners and the 6008-SV scanner. If you use
that command, you must modify the command to specify the rack size.
The 6008-SV1R and 6008-SV2R also offer improved block transfer
operations. In addition to single block transfer operations, the 6008-SV1R
and 6008-SV2R support continuous block transfer operations. A single
block transfer is a single read or write transfer to a specific intelligent I/O
module. If your application needs to continuously poll a module to receive
up-to-date data, use a continuous block transfer request. The continuous
block transfer requests uses less programming overhead than programming
a single block transfer request each time you need the data.
Comparison to
6008ĆSV Scanner