Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 90)

Operating Functions
Chapter 5
5–53
Example:
u10 REM PRINT CONTENTS OF BTW BUFFER
u20 C=(XBY(7D0AH)*100H)+XBY(7D0BH)
u30 FOR I=0 TO 128
u40 PH0. XBY(C+I),
u50 NEXT I
u60 END
This routine transfers the block-transfer-read (BTR) buffer to the auxiliary
processor on the BASIC Module for use in the next BTR request from the
host processor. If no data transfer occurs within 2 seconds the routine
returns to BASIC without transferring data. This routine has no input
arguments and one output argument (the status of the transfer). A non-zero
returned means that no transfer occurred and the CALL timed out. A zero
returned means a successful transfer.
Example:
u10 CALL 2
u20 POP X
u30 IF X tu 0 PRINT “TRANSFER UNSUCCESSFUL”
This routine transfers the block-transfer-write (BTW) buffer of the
auxiliary processor on the BASIC Module to the BASIC BTW buffer. If no
data transfer occurs within 2 seconds the routine returns to BASIC with no
new data. This routine has no input arguments and one output argument
(the status of the transfer). A non-zero returned means that no transfer
occurred and the CALL timed out. A zero returned means a successful
transfer.
Example:
u10 CALL 3
u20 POP X
u30 IF X tu 0 PRINT “TRANSFER UNSUCCESSFUL”
5.7
Data Transfer Support
Routines (continued)
5.7.1
Update Block-Transfer-Read
Buffer (timed) – CALL 2
5.7.2
Update Block-Transfer-Write
Buffer (timed) – CALL 3