Rockwell Automation 2755-DM9, -DM9E High Speed Decoder - Manual (Page 12)

Chapter 2
Description of Hardware
2–2
You can program many of the operating parameters of the decoder. This
programming capability allows you to adapt the decoder to a specific
application. You can:
•
Specify decoder operating modes.
•
Select types and lengths of symbols to be read.
•
Select communications protocols used when communicating with a
computer or programmable controller.
•
Enter up to eight match codes.
•
Specify up to eight discrete outputs.
•
Specify up to eight discrete outputs.
You can select continuous scanning or you can define what event will trigger
the label reading process. You can specify the trigger to be:
•
A signal from the package detector connected to the laser scan head.
•
A command received from a host computer.
•
The decoder’s internal timer.
The decoder can communicate with a host computer using the following
standards:
•
RS-232.
•
RS-422.
•
RS-485 (Multi-drop Network using Allen-Bradley DH485 protocol).
The decoder will operate with the following scan heads:
•
Catalog No. 2755-L7 and -L9 Medium and High Speed, Industrial Bar
Code Scanners.
•
Catalog No. 2755-L4F, -L4R, and -L5R Medium Speed, Enhanced,
Material Handling Scanners.
Note: We have not listed complete catalog numbers for the scan heads.
These scan heads are available in a variety of configurations.
Figure 2.1 shows the decoder. The decoder is housed in a steel enclosure
(NEMA 1 rating). The decoder enclosure is 14” wide, 2.81” tall, and 10.75”
deep (refer to Chapter 5 for installation drawing). On top of the decoder are
fourteen indicator LEDs which indicate the status of the decoder and the
outputs (refer to Indicator Section in this chapter). On the back of the
decoder are the communications ports (refer to Communications Port Section
in this chapter). A separate removable cover allows for easy access to the
discrete output modules and fuses (refer to Output Module Section in this
chapter). Connectors are also provided for the laser scan head and power
line connector cables.
(Continued)
Laser Scan Heads
Physical Description