Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 238)

Chapter
Call Routines 0–68 12
12 -48
Input Argument Eight
The eighth input argument is the selection of the BTR buffer and/or string:
0 = BTR buffer
2 = internal string
4 = BTR buffer and internal string
If you choose internal string (2), you can execute CALL 29 (page 12 -18)
to initiate each data transfer without requiring PLC processor interaction.
Input Argument Nine
The ninth input argument is always 1.
Input Argument Ten
The tenth input argument is the string number. If the eighth input
argument does not select internal string usage, the value of this input
argument is ignored, but you must still PUSH it.
Output Argument One
The output argument is the status of the call. It has these values:
0 = successful
1 = disabled
2 = bad input parameter
3 = port DH-485 not enabled (DF1 enabled)
4 = string is too small
5 = string is not dimensioned
6 = JW5 not in 16-point position
Whenever an attempt is made to read a remote packet, the status of the
read is placed into BTR word 1. These values have the same definition as
the output values in CALL 92 (page 13 -26). The status becomes valid
when the BASIC module sets the input image table bit 14.
Syntax
PUSH type of DH-485 READ command
PUSH remote node address
PUSH remote file number
PUSH remote file type
PUSH starting word offset of remote file
PUSH number of words to be transferred
PUSH message time-out value
PUSH selection of destination file (BTR buffer)
PUSH 1
PUSH string number
CALL 49
POP CALL 49 status