Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 333)

15B. Driver488/SUB, W31, W95, & WNT III. COMMAND REFERENCES - 15. Command References
III-318 Personal488 User’s Manual, Rev. 3.0
EXAMPLE errorcode = ClockFrequency(ieee, 8);
The ClockFrequency command specifies the IEEE 488 adapter internal clock frequency. The clock
frequency depends upon the design and jumper settings of the interface board. The specified clock
frequency must be the actual clock rate in megahertz (MHz) rounded up to the nearest whole number of
megahertz. The MP488 and MP488CT boards use a fixed clock frequency of 8 MHz.
Note: This command is not applicable to the NB488.
Close
SYNTAX int pascal Close(DevHandleT devHandle);
devHandle refers to either an IEEE 488 interface or an external device.
RETURNS -1 if error
MODE Any
BUS STATES Completion of any pending I/O activities
SEE ALSO OpenName, MakeDevice, Wait
EXAMPLE errorcode = Close(wave);
The Close command waits for I/O to complete, flushes any buffers associated with the device that is
being closed, and then invalidates the handle associated with the device.
ControlLine
Driver488/SUB only
SYNTAX int pascal ControlLine(DevHandleT devHandle);
ControlLine returns a bit mapped number.
devHandle refers to the I/O adapter. If devHandle refers to an external device,
the ControlLine command acts on the hardware interface to which the
external device is attached.
RESPONSE -1 if error,
otherwise, a bit mapped integer indicating the value of the
control lines.
MODE Any
BUS STATES None
SEE ALSO TimeOut
EXAMPLES result = ControlLine(ieee);
printf(“The response is %X\n”,result);
The ControlLine command may be used on either IEEE 488 devices or Serial devices. If the device
specified is an IEEE 488 device, this command returns the status of the IEEE 488 bus control lines as
an 8-bit unsigned value (bits 2 and 1 are reserved for future use), as shown below:
8 7 6 5 4 3 2 1
EOI SRQ NRFD NDAC DAV ATN 0 0
If the device refers to a Serial device, this command returns the status of the Serial port control lines as
an 8-bit unsigned value (bits 8 and 7 are reserved for future use), as shown below:
8 7 6 5 4 3 2 1
0 0 DSR RI DCD CTS DTR RTS
A fuller description of the above bus line abbreviations are provided below: