Rockwell Automation 1775-S4B,D17756.5.3 User Manual SCANNER/MSG HND - Manual (Page 34)

Operating the LIST Function
Chapter 4
4Ć12
If you select an I/O channel, you can make the following selections for the
corresponding I/O communication channel:
Communication rate (baud)
I/O
scan
We explain these selections in the following sections.
You can select one of the following communication rates for the
corresponding I/O communication channel:
If you select: Then:
57.6 kbaud
115.2 kbaud The maximum I/O channel cable length can be 10,000 feet.
The maximum I/O channel cable length can be 5,000 feet.
You can change the order of execution for an I/O scan of the corresponding
I/O communication channel by selecting the I/O scan selection in LIST.
When you configure an I/O channel for I/O scan, list the I/O chassis in the
order that you want the 1775-S4B scanner to communicate with them. This
allows you to assign a higher priority to some I/O chassis than to others by
listing the higher priority chassis more than once.
As an example, if there are six entries in the I/O chassis list, and entries 1
and 4 are the same, then the chassis listed under entries 1 and 4 will be
updated twice as often as the other chassis. You can list a chassis as often
as you desire, provided that the list contains no more than 32 entries.
Each I/O chassis is listed once in the default configuration at initial
powerup or after an autoconfigure.
When forming the I/O chassis list, remember the following considerations:
Rack numbers which are not assigned consecutively cause greater
memory requirements by allocating memory for unused racks.
No more than 16 I/O adapters can connect to one I/O communication
channel on the 1775-S4B scanner.
No more than 16 different rack numbers can be assigned to one
1775-S4B scanner.
When using complementary or duplicate I/O, two chassis with the same
rack and starting module group numbers must be on different channels
4.3.1
I/O Channel Configuration
4.3.1.1
Communication Rate
4.3.1.2
I/O Chassis Scanning
Sequence