Rockwell Automation 2755-L7, -L9 Scanners - Manual (Page 9)

Chapter 2
Product Description
2–2
Figure 2.2 illustrates the average reading ranges, relative to the symbol’s
minimum bar width, that you should expect when using an L7 scanner with
your Catalog No. 2755–DM9 Decoder.
① Scan Range will vary with symbol quality, pitch and skew. This application was based on no more than 5
°
pitch and 30
°
skew, with full scan beam
(Figure 5.3). Refer to Chapter 3, Installation Considerations when reading labels with more than 20
°
pitch.
2755–L7SA
2755–L7RA
50
127.0
40
101.6
2755–L7SB
2755–L7RB
2755–L7SD
2755–L7RD
2755–L7SC
2755–L7RC
35
88.9
30
76.2
25
63.5
20
50.8
15
38.1
10
25.4
5
12.7
Scan Range (from face of scanner) ①
45
114.3
Minimum Bar Width
Inches
Centimeters
Figure 2.2
Average Scan Range vs. Minimum Bar Width for L7 Scanner
50
1.27
45
1.14
5
.13
40
1.02
35
.89
30
.76
25
.64
20
.51
15
.38
10
.25
Mils
Millimeters
The following table compares the minimum bar width to the scan range of
each catalog number.
Minimum Bar
Width
Scan Range ① Catalog Number
Mils mm Inches Centimeters Side Scanning
Raster
Scanning
7.5
10
20
.19
.25
.51 6.5 – 8.5
6.0 – 9.0
5.0 – 11.0
16.5 – 21.6
15.2 – 22.9
12.7 – 27.9
2755–L7SA ① 2755–L7RA ①
11
20
25
.28
.51
.64 8.5 – 13.5
5.5 – 19.0
3.5 – 22.0 21.6 – 34.3
14.0 – 48.3
8.9 – 55.9
2755–L7SB 2755–L7RB
16
25
35 .41
.64
.89 10 – 23
8 – 29
6 – 35
25.4 – 58.4
20.3 – 73.7
15.2 – 88.9
2755–L7SD 2755–L7RD
20
35
50 .51
.89
1.27
16 – 35
8 – 50
8 – 50
40.6 – 88.9
20.3 – 127
20.3 – 127 2755–L7SC 2755–L7RC
① When using ‘‘A’’ range scanners to read labels with high paper noise, increasing the skew to 25 _ will enhance performance.
L7 Reading Ranges