Rockwell Automation 1771-IJ_IK IK ENCODER/COUNTER MODULES - Manual (Page 13)

Chapter
2
Publication 1771ĆUM006B-EN-P - June 2002
Preliminary Adjustments
The module has programming options (Table 2.A) that are selected
by setting the five switches on the programming option switch
assembly (SW-1). These options include the choices between
encoder and counter operation, block transfer or single transfer, BCD
or binary data formats and count resolution in the encoder mode.
Table 2.A
Programming Option Switch Assembly SWĆ1
1 2, 3 4 5
On
Single
Transfer
See Table 2.B
Multiplier for
Count
Resolution
Encoder
Mode Binary
Off Block
Transfer
Counter
Mode BCD
Block transfer/single transfer (switch 1) - Use single transfer
programming only when the module is in a local I/O chassis. This
type of programming shifts a single word of data each program scan
from the processor’s data table to the module. It therefore takes
three program scans to send a new control word and the two preset
values to the module. However, once new data has been sent to the
module, it will remain active until another transfer updates it.
The input status word will always appear at the proper address
location in the input image table. To use single transfer
programming, switch 1 must be set to single transfer (on).
Block transfer moves all three data words from the processor to the
module in a single scan. Since the module has bidirectional block
transfer, the processor must also be programmed to read for block
transfer, or the data table will not display the status word. To use
block transfer, switch 1 must be set for block transfer (off).
General
Block Transfer/Single
Transfer