Rockwell Automation 2755-SNx Adaptascan Bar Code Readers - Manual (Page 203)

11–3 Communicating with a PLC-5 Processor on a DeviceNet Network
Publication 2755-6.8
This section provides the PLC-5 ladder logic program and data
monitor results. The ladder logic uses:
•
File N23 as the BTR file
•
File N22 ad the BTW 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 PLC-5 data table.
File Location Description
3
Word 0 Status word for SDN Scanner
N23
Word 1 Bit 15 ‘New Message Being Sent’ bit from AdaptaScan Reader
Word 0 Status word
N22 Word 0 Bit 0
1=SDN Scanner in run mode
0=SDN Scanner in idle mode
Idle mode is used to write the DeviceNet
configuration to the SDN Scanner.
Word 1 Bit 7 ‘Send Message’ bit to AdaptaScan Reader
Message AddressingC
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.
PLC Ladder Logic