Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 192)

Chapter
Call Routines 0–68 12
12 -2
This routine initiates a full reset. This is similar to a re-boot or pressing
the reset button. The BASIC module reacts to this reset the same as it does
when you turn on power to your I/O chassis backplane (page1 -13).
Input and Output Arguments
This routine has no input or output arguments.
Syntax
CALL 0
Example
> 10 CALL 0
This routine does nothing. You return back to the main program.
Use this routine to send data to the PLC processor. CALL 2 transfers the
block-transfer-read (BTR) buffer to the auxiliary processor on the BASIC
module for use in the next BTR request from the PLC processor.
If a data transfer does not occur within 2 seconds the routine returns to
your BASIC program without transferring data. BASIC execution halts
until the BTR occurs or the call times out.
Whenever this call is active bit 2 (the sync BTR bit) of the PLC input
image table is set. You can use this bit to trigger a BTR rung. If you are
using CALLs 33, 34, 49, 50, 118, 122, or 123 you must use these bits to
perform synchronous block transfers. Synchronous block transfer is only
supported in PLC-5 processors; use the sync BTR bit with a PLC-5.
Input and Output Arguments
This routine has no input arguments and one output argument. The output
argument is the status of the transfer. If CALL 2 times out before a
successful block transfer is complete, the status code returned is 89 (59H).
A time-out occurs if a previous CALL 2 initiated a block transfer read, and
the BTR was not serviced by the PLC processor. CALL 2 does not return
an error code if a mismatch occurs in block transfer length between the
BASIC module and the block transfer read instruction.
0 = a successful transfer
89 = a transfer did not occur and the call timed out
Syntax
CALL 2
POP status of transfer
Example
>10 CALL 2
>20 POP X
>30 IF X <> 0 PRINT “TRANSFER UNSUCCESSFUL”
CALL 0: Reset Module
CALL 1: No Operation
CALL 2: Timed Block-
Transfer-Read Buffer