10-36
2000-OSM, F1
msg_type%
is the message type; for Vista BASIC this is always 0.
block_type%
is the block type; for Vista BASIC this is always 0.
flags%
is the message flag; for Vista BASIC this is always 0.
Example: shown
below
SEND MESSAGE Command
Description:
Sends a UDP message from one VistaNET device to another.
Syntax:
SND_MSG(header$,data$)
Comments:
header$
is the UDP message header constructed using the BUILD
HEADER
Command.
data$
is the ASCII data block to be sent.
Example: shown
below
SEND REPLY Command
Description:
Sends a VistaNET reply to another VistaNET device.
Syntax:
SND_RPL(header$,data$)
Comments:
header$
is the UDP message header received using the RECEIVE
HEADER
Command.
data$
is the ASCII data block to be sent.
Example: shown
below
RECEIVE HEADER Command
Description:
Receives a UDP message header from a VistaNET device.
Syntax:
HDR$ = RCV_HDR$
Comments:
HDR$
is a string variable which will store the received UDP header
information. If the length of HDR$ is 0 upon executing this command, no
message has been received.
Example: shown
below
RECEIVE DATA Command
Description:
Receives a message from a VistaNET device.
Syntax:
DATA$ = RCV_DATA$
Comments:
DATA$
is a string variable which will store the received data.
Example: shown
below
VistaNET Messaging Example
The sending application is located at VistaNET address 0.1.0.5. The receiving application is located
at VistaNET address 0.1.0.4
At 0.1.0.5 (the sending end):
First the message header is built:
0010 HDR$ = BLD_HDR(1,4,518,1,0,0,0)
Then the message is constructed: 0020 DATA$ = “THIS IS THE MESSAGE”
The message is sent:
0030 SND_MSG(HDR$,DATA$)
At 0.1.0.4 (the receiving end):
A BASIC program (usually in real-time BASIC table number 8) is written to accept VistaNET
messages:
0010
HDR$
=
RCV_HDR$
0020 IF LEN(HDR$) = 0 THEN END
0030
DATA$
=
RCV_DATA$