Rockwell Automation 2755-SNx Adaptascan Bar Code Readers - Manual (Page 143)

9–3 Communicating with an SLC 5/03 Processor on a DeviceNet
t
Network
Publication 2755-6.8
This section provides the SLC ladder logic program and data monitor
results. The ladder logic uses:
•
File N23 as the SLC interface to M1 file
•
File N22 as the SLC interface to M0 file
The data table shows file N23 after the AdaptaScan Reader
successfully reads and transfers data ‘0300’ (from a 4 character,
Interleaved 2 of 5 symbol) to the SLC data table.
File Location Description
Discrete
Output O
Word 0 Bit 0
1=SDN card in run mode
0=SDN card in idle mode
3
Word 0 Status word
N23
Word 1 Bit 15 ‘New Message Being Sent’ bit from AdaptaScan Reader
Word 0 Status word
N22
Word 1 Bit 7 ‘Send Message’ bit to AdaptaScan Reader
Message AddressingA
Message Data is formatted the same as messages sent through the
serial port. When setting up the DeviceNet scanner for addressing
message data, use the following table.
Description Word #
Byte #
➀➁
Number of Characters (LSB) 2
Number of Characters (MSB)
2
3
First Message Character
(Beginning of Message)
3
4
Other Message Characters
from left to right
3
5 !
Last Message Character
(End of Message) 3+N where N is the number of characters in
the message.
➀
Bytes #0 and #1 (word 1) are reserved for Discrete I/O.
➁
Poll Rx Size = 4 + (# of Characters in string).
Message data is addressed and sent to other DeviceNet devices
through a DeviceNet scanner (Catalog No. 1771-SDN or
1747-SDN). To configure the scanner, you will need to provide the
size of the message data, the beginning byte and bit number of the
message and the destination of the message data.
SLC Ladder Logic