Allen-Bradley devicenet modules in logix5000 control systems Manual Do Utilizador

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Publication DNET-UM004A-EN-P - March 2004
14-2        Using FLEX™ I/O Modules on a DeviceNet Network
Tally Memory 
Requirements
The Flex I/O adapter 1794-ADN packs the data of its I/O modules into 
a contiguous block of input or output bytes. By default, the modules 
share DINT elements in the scanner.
To determine the amount of scanner memory required for your 
adapter and its I/O modules
As an option, give each module its own memory location (DINTs) 
within the scanner. This may make your programming easier. See Give 
a Value Its Own Memory Location
 page A-1.
Device
Input Size of 
Device
(bytes)
Output Size 
of Device
(bytes)
Flex I/O adapter—1794-ADN
2
0
digital output module—1794-OB16
2
2
digital input module—1794-IB16
2
2
Total
6
4
Device
Address
Input Size of 
Device
(bytes)
Input Memory 
in Scanner 
(DINTs)
Output Size 
of Device
(bytes)
Output Memory 
in Scanner 
(DINTs)
start/stop buttons
1
1
1
1
motor starter
4
1
4
1
Flex I/O adapter w/ modules
6
2
4
1
Total
1. Add the input bytes of each module + 2 bytes for the adapter.
2. Add the output bytes of each module (0 for 
the adapter).
3. Add the totals to the main tally.
sub-tally
main tally