99
Set necessary information in IR area.
1
0
1
0
1
0
Data
transfer
Data processing
Preparation of data
in PC’s data areas
Beginning transfer number
IR n+2, bits 15 to 08
Beginning word number
IR n+3
PC data area/no. of transfers
IR n+4
TRANSFER DATA
IR n, bit 10
Transfer Completed flag
IR n+5, bit 10
Busy flag
IR n+5, bit 12
4–9–3
Present Position Preset
You can change the function of the TRANSFER DATA command bit with a
setting in the IR area. If bit 15 of IR word n+2 is set to 1, the TRANSFER
DATA command bit (bit 10 of IR word n) is set to either preset or change the
present position. This command can be used to eliminate the need to ex-
ecute ORIGIN SEARCH to establish position. Since the origin, present posi-
tion, and so on, are not known when the Position Control Unit is powered up,
it is ordinarily necessary to execute ORIGIN SEARCH first. You can use the
present position preset function instead, however, when it is sufficient to set a
specific numerical value and use that position as a reference point. In such
cases, the origin will be defined in relation to that position, and there is no
need to search for the origin first.
No data is retained in the Position Control Unit once power is turned OFF.
When the present position needs to be retained, copy it (words n+8 and n+9)
to either the HR or DM area, and then restore it by using TRANSFER DATA
the next time the Unit is powered up.
The following programming example shows IR n+8 data moving to HR 00
and IR n+9 data moving to HR 01. If there is no origin, bit 11 of IR word n+5
(the No-origin flag) turns ON (goes to 1). As long as there is an origin and the
present position data is valid, the present position will be transferred.
Retaining Present Position
TRANSFER DATA
