Rockwell Automation 1771-IJ_IK IK ENCODER/COUNTER MODULES - Manual (Page 35)

5–5 Single Transfer Programming
Publication 1771ĆUM006B-EN-P - June 2002
Figure 5.3
Preset Word #2 Ć Single Transfer
17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00
Most
Significant
BCD Digit
(0-9)
Middle
(0-9)
Least
Significant
(0-9)
or, 12-bit binary value
Preset Value
0 1 0 0
15954
Bits 14Ć17 = Word Select Bits,
must have this pattern for Preset
Word #2..
1
Module switch selection determines whether bits 00Ć13 are of binalry or BCD format
BCD Digit
BCD Digit 1
1
1
1
Note that bits 14-17 have a unique coding to identify each preset
word.
Note: If BCD operation has been switch selected, only BCD digits
should be entered in the data table word output to the module. If
non-BCD digits are entered in a preset value, the module sets its
default preset value to 000 for the word.
Single transfer programming uses the I/O scan for bidirectional
module/processor communication. The I/O scan is an automatic
function of the processor during which it performs two operations: it
writes output image table data to I/O modules and reads I/O module
data into the input image table. The write cycle of the I/O scan must
be manipulated by the program for communication with the
encoder/counter module. By this manipulation, up to three 16-bit
words are sent to the module by using one output image table word.
The read cycle of the I/O scan is also used, but is not manipulated by
the program since only a single input status word is read from the
module.
Single Transfer
Description