Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 321)

15A. Driver488/DRV Commands III. COMMAND REFERENCES - 15. Command References
III-306 Personal488 User’s Manual, Rev. 3.0
The RESUME command unasserts the Attention ( ATN ) bus signal. Attention is normally kept asserted by
Driver488, but it must be unasserted to allow transfers to take place between two peripheral devices. In
this case, Driver488 sends the appropriate
Talk and Listen addresses, and then must unassert
Attention with the RESUME command.
If MONITOR is specified, then Driver488 monitors the handshaking process but does not participate in
it. Driver488 takes control synchronously when the last terminator or EOI is encountered. At that
point, the transfer of data stops. The FINISH command must be called to assert Attention and release
any pending holdoffs to be ready for the next action.
SEND
SYNTAX SEND[;] subcommand[subcommand...]
RESPONSE None
MODE CA (any subcommands)
Any (DATA and EOI subcommands only)
BUS STATES User-defined
SEE ALSO OUTPUT
EXAMPLES PRINT#1,”SEND MTA UNL LISTEN16 DATA ‘T1S0R2X’”
is the same as
PRINT#1,”OUTPUT16;T1S0R2X”
PRINT#1,”SEND CMD 128,0,10 DATA 156,35 EOI ‘ABC’”
sends the following byte sequence:
Data
10000000
00000000
00001010
10011100
00100011
01000001
01000010
01000011
ATN
ATN
ATN
*ATN
*ATN
*ATN
*ATN
*ATN
*ATN
EOI
*EOI
*EOI
*EOI
*EOI
*EOI
*EOI
*EOI
EOI
The SEND command provides byte-by-byte control of data and command transfers on the bus and gives
greater flexibility than the other commands. This command can specify exactly which operations
Driver488 executes. The following subcommands are available within the
SEND command:
SEND Subcommand Operation (Bus Command or Data Transfer)
UNT Send the Untalk bus command. ATN is asserted.
UNL Send the Unlisten bus command. ATN is asserted.
MTA Send the My Talk Address bus command. ATN is asserted.
MLA Send the My Listen Address bus command. ATN is asserted.
TALK addr Send the Talk Address Group (TAG) bus command. ATN is asserted.
LISTEN addr[,addr...] Send the Listen Address Group (LAG) bus command. ATN is asserted.
DATA {‘data’|number}
[,{‘data’|number}...]
Send character strings data or characters with numeric ASCII values char.
ATN unasserted.
EOI {‘data’|number}
[,{‘data’|number}...]
Send character strings data or characters with numeric ASCII values char.
ATN unasserted. EOI is asserted on the last character.
CMD {‘data’|number}
[,{‘data’|number}...]
Send character strings data or characters with numeric ASCII values char.
ATN asserted.
The DATA , EOI and CMD subcommands send data bytes or characters over the bus. The characters to be
sent are specified either as a quoted string ( ‘data’ ) or as individual ASCII values
( number[,number...] ). For example, DATA‘R0X’ sends the characters R , 0 , and X to the active
listeners, while DATA13,&H0A sends the carriage return and line feed. Multiple quoted strings or
ASCII valued bytes may be specified by separating them with commas. The EOI subcommand is
identical to the DATA subcommand except that the End-Or-Identify ( EOI ) signal is asserted on the
transfer of the last character.