Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 245)

Chapter
Call Routines 0–68 12
12 -55
Input Argument Eight
The eighth input argument is the selection of the source BTW buffer or the
internal string:
0 = BTW buffer
2 = 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.
The output table bit 15 also initiates a string transaction.
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 validation of the call parameters. 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 is not in 16-point position
Whenever you attempt to write to a remote node, the BASIC module
places the status of the write into the BTR buffer word 1. The status values
have the same definition as the output values in CALL 93
(page 13 -29).