User Manual

Chapter 4
Module Configuration
4–2
Starting I/O Group Number (SW1-7 and SW1-8)
The starting I/O group number is the first word assigned to the DCM from
the scanner’s image table. The starting I/O group number must be an even
number from 0 to 6 and is dependent upon whether the DCM has been
configured as a full, 3/4, 1/2, or 1/4 rack. The first word transferred is
always the status word for the DCM.
Rack Size Number of RIO Words Transferred Total Words
1/4 Logical Rack 1 Status and 1 Data 2
1/2 Logical Rack 1 Status and 3 Data 4
3/4 Logical Rack 1 Status and 5 Data 6
Full Logical Rack 1 Status and 7 Data 8
Reference the table below to set the starting I/O group number.
Starting I/O Group Number SW1-7 SW1-8 Valid Rack Configuration
0 ON ON All
2 ON OFF 3/4, 1/2, 1/4
4 OFF ON 1/2, 1/4
6 OFF OFF 1/4
Example of different starting groups:
A SS T T U W O R D
Group 0, W ord 0
Group 1, Word 1
Group 2, Word 2
Group 3, Word 3
Group 4, Word 4
Group 5, Word 5
Group 6, Word 6
Group 7, Word 7
DCM 2 Rack Size
= 1/2 Rack
RR
In the above image map example, selecting I/O Group Number 2 instructs the scanner
to address Word 2 as the beginning of DCM 2 image. In this example, a half rack is
selected for DCM 2 (using SW2 switches 5 and 6). Since Word 2 is the first word
assigned, it becomes the Status Word.
DCM 1 Rack Size
= 1/4 Rack
DCM 3 Rack Size
= 1/4 Rack
Starting Group 2
Starting Group 0
Starting Group 6
A SS T T U W O R D
A SS T T U W O R D
Decimal 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Octal
Bit Number:
17 16 15 14 13 12 11 10 7 6 5 4 3 2 1 0
DIP Switch 1 Settings