Rockwell Automation 1746-BAS BASIC LANGUAGE - Manual (Page 203)

Publication 1746-RM001A-US-P
Input Functions 13-13
CALL 29 – Read/Write to
a PLC/SLC from the
Module Internal String Purpose
Use CALL 29, in conjunction with CALLs 122 or 123, to communicate between
remote PLCs and the module internal string without local SLC processor
interaction. You can also use CALL 29, in conjunction with CALLs 27 or 28, to
communicate between remote SLCs and the module internal string without local
SLC processor interaction. CALLs 27, 28, 122, or 123 must be executed within the
BASIC program before CALL 29.
CALL 29 is active when the internal string is the only choice in CALLs 27, 28,
122, or 123. In this situation, it is not practical to use the SLC input and output
image files to begin the transfer and to pass the status. The SLC processor does not
need to be involved. If an SLC file is chosen instead, the local SLC processor
controls the transfer with the input and output image bits. In this instance, a status
of 255 is returned when CALL 29 is attempted.
One argument is PUSHed and one argument is POPped. The input argument is
the CALL to be activated (CALL 27, 28, 122, or 123).
0000
T4:0
DN
EN
DN
TON
Timer On Delay
Timer
T4:0
Time Base 0.01
Preset 1000
Accum 0
0001
T4:0
DN
O:1
10
L
O:1
10
0002
EQU
Equal
Source A
I:1.1
Source B
0
0
COP
Copy File
Source
#M1:1.0
Dest #N10:20
Length 21
NEQ
Not Equal
Source A
I:1.1
Source B
0
0 0
0
MOV
Move
Source
I:1.1
Dest
N10:20
L
O:3
0
U
O:1
10
0003
I:2.0
0
I:1.0
10
OSR
B3:0
0
U
O:3
0
0004 END
Initiate CALL 27 in the
module every 10 seconds via
timer T4:0.
CALL 27 Request Bit
Status OK
Buffer Data if Status OK
Bad Command Status Buffer Status Byte if Non-zero
Command Failed Indication
CALL 27 Request Bit
Command Failed Indication
Reset Alarm P.B.