Rockwell Automation 2755-DM9, -DM9E High Speed Decoder User Manual
Page 118
Chapter 8
Host Commands Using the RS-485 Interface
8–6
HI- AND LOW ADDRESS (Bytes 4 & 5) - These bytes specify the area of
memory in the decoder that is going to be read. There are four readable areas
in the decoder’s memory (memory addresses are provided in hexadecimal):
1) Current Bar Code Data - Address 100 to 3FF (hex). The bar code data is
stored in the decoder’s host port buffer as a packet, each packet contains the
results of one read operation. The data is at address 100 (hex).
Note: Unlike the other readable areas of the decoder’s memory, the host
buffer may or may not contain data.
2) Decoder Configuration Block- Address 400 to 5FF. Refer to Appendix D
for the addresses of the configuration parameters.
3) Status/Counters- Address 600 to 6FF. Table 8.B provides the addresses of
the status and counters.
Address
(Hexadecimal)
Contents
Number of
Bytes
600
Package counter
.
4
604
Output Counter Number 1
4
608
Output Counter Number 2
4
60C
Output Counter Number 3
4
610
Output Counter Number 4
4
614
Output Counter Number 5
4
618
Output Counter Number 6
4
61C
Output Counter Number 7
4
620
Output Counter Number 8
4
624
No-Read Counter
4
4) Last Message to Host- Address 800.
SIZE OF DATA (Byte 6 )- The size of data field specifies the number of
bytes that will be returned. A maximum of 124 bytes may be read.