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Sample for GPIB-1, PCIGPIB-1, USB-GPIB-1
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Sample Source for Borland Delphi
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program GPIB_CONSOLE_APP;
{*
// gpib.pas : Sample project for Borland Delphi shows how to program the
// GPIB-1, PCIGPIB and USB GPIB Modules
//
// Author: Michael Reimer, QUANCOM Informationssysteme GmbH, Germany
//
// Website: http://www.quancom.de
// Product:
// GPIB PCI Controller http://www.quancom.de/qprod01/eng/pb/pcigpib_1.htm
// GPIB ISA Controller http://www.quancom.de/qprod01/eng/pb/GPIB_1.htm
// GPIB USB Controller http://www.quancom.de/qprod01/eng/pb/usb_gpib_1.htm
// Information:
//
// To use the QLIB Commands in your source, do the following:
//
// (1) Add statement {$INCLUDE QLIB.pas} to your source file.
// (2) Copy QLIB.PAS from QLIB Installation Directory
// d:\program files\quancom\qlib32\include to your
// working directory
*}
{$APPTYPE CONSOLE}
{$INCLUDE QLIB.pas}
{$X+}
var handle: longint;
result: longint;
listener: longint;
talker: longint;
buffer: string;
s: string;
serial_poll_byte: longint;
device: longint;
begin
{*
// The following sequence tries to find the
// Bus Type ( PCI, ISA or USB ) of the
// installed GPIB Controller
*}
handle := QAPIExtOpenCard(PCIGPIB,0);
if ( handle = 0 ) then
begin
handle := QAPIExtOpenCard(USBGPIB,0);
if ( handle = 0 ) then
begin
handle := QAPIExtOpenCard(GPIB,0);
end;
end;
{*
// The handle is <> NULL if there is a GPIB Controller installed
*}
if ( handle = 0 ) then
begin
s := 'No QUANCOM GPIB Controller found!';
writeln(s);
halt(0);
end;
{*
// Ok, we found a QUANCOM GPIB Controller Card
// Now we can send a string to the listner with address 3
// Change the address to the appropriate address for your
// device ( normally set by DIP-Switches on the back side )
// ---------------------------------------------------------------------------
// PART 1a: Writing a string to a IEEE 488, GPIB, HPIB Device
//
// Listener: A device capable of receiving data over the interface
// when addressed to Listen by the active controller. Examples of such
// devices are printers, programmable power supplies, or any other
// programmable instrument. There can be up to 14 Listeners on the GPIB Bus
// at one time.
// ---------------------------------------------------------------------------
// Select the listener address, which is set by a DIP-Switch on the
// back side of your instrument.
*}
listener := 3;
// Send "z" to the listener 3, which resets the DMM to the initial settings.
s := 'z'#0;
if ( QAPIExtWriteString(handle, listener, Pchar(s), Length(s),0) = 0) then
begin
writeln('Writing to device ', listener, ' was successful.');
end
else
begin
writeln('Writing to device ', listener, ' failed.');
end;
{*
// ---------------------------------------------------------------------------
// PART 1b: Reading a DMM or any other IEEE-488 device
//
// Talker: A device capable of transmitting data over the interface when
// addressed to talk by the active controller. Examples of such devices
// are voltmeters, data-acquisition systems, or any other programmable
// instrument. There can be only one addressed talker on the GPIB Bus at one
// time.
// ---------------------------------------------------------------------------
// Select the talker address, which is set by a DIP-Switch on the
// back side of your instrument.
*}
talker := 3;
SetLength(buffer,1024);
{*
// Read value from DMM with talker address 3
*}
result := QAPIExtReadString(handle, talker, PChar(buffer), Length(buffer), 0);
if ( result <> 0 ) then
begin
writeln('Reading from device', talker, ' was ', buffer);
end
else
begin
writeln('Reading from device ', talker, ' failed.');
end;
{*
// ---------------------------------------------------------------------------
// PART2: Checking whether a device has requested service ( SRQ Service Request)
//
// A device can interrupt the active controller by asserting the SRQ line. The
// SRQ is a single line, and if there are multiple devices on the GPIB Bus that
// have been configured to assert an SRQ, the active controller will have
// to "poll" the devices to figure out which one actually asserted the SRQ.
// More than one device could in principle assert an SRQ at the same time. The
// active controller can poll the devices in one of two ways: serial poll
// or parallel poll.
// ---------------------------------------------------------------------------
*}
result := QAPIExtSpecial(handle, JOB_READSRQ, 0, 0);
if (result <> 0) then
begin
writeln('SRQ was asserted.');
end
else
begin
writeln('SRQ was not asserted.');
end;
{*
// ---------------------------------------------------------------------------
// PART3: Reading Serial Poll Status from DMM
//
// In a serial poll, the active controller asks each device in turn to
// send back a status byte that indicates whether the device has asserted
// the SRQ. Bit 6 of this byte (where the bits are numbered 0 through 7) is set
// if the device is requesting service. The definition of the other bits
// is device dependent (under 488.1 at least; 488.2 provides a much more
// concise definition of the status byte).
//
// The program has to perform this same sequence with every device
// it needs to poll.
// ---------------------------------------------------------------------------
// We poll all devices from 1 to 15 here. This is normally not nescessary and
// very time consuming. Poll only valid devices on the GPIB Bus.
*}
serial_poll_byte := 0;
for device := 1 to 15 do
begin
result := QAPIExtSpecial(handle, JOB_SERIALPOLL, device, LongInt(@serial_poll_byte));
if ( result <> 0 ) then
begin
if ((serial_poll_byte and $40) = 0) then
begin
{* check for bit 6 = device requested service *}
writeln('Device ', device, ' requested service and returned status byte ' , serial_poll_byte);
end
else
begin
writeln('Device ', device, ' no SRQ requested. Status is ', serial_poll_byte);
end;
end
else
begin
writeln('No answer from device ', device);
end;
end;
{*
// ---------------------------------------------------------------------------
// PART4: Send a command to DMM
//
// The following commands are accepted by all devices on the GPIB Bus
// simultaneously. The address part will be ignored.
//
// - JOB_DCL (Device Clear): The DCL command causes all devices to return to a device
// dependent initial state.
//
// - JOB_LLO (Local Lockout): The LLO command disables the return-to-local front
// panel key on the device. The user can no longer change the device settings
// from its front panel.
//
// The following commands need an address and are only accepted by addressed
// devices. Whether the devices are the listeners or the talkers depends on the
// command. The three commands are as follows:
//
// - JOB_GET (Group Execute Trigger): The GET command tells all the addressed
// listeners to perform some device-dependent function, like take a measurement.
// GET allows for synchronizing a measurement function between multiple devices.
// This is only used in specialized cases.
//
// - JOB_SDC (Selected Device Clear): The SDC command resets the addressed listeners
// to a device-dependent state. It performs the same function as DCL,
// but only resets the addressed listeners, not all the devices.
//
// - JOB_GTL (Go To Local): The GTL command sets the addressed listeners back to
// local mode.
// ---------------------------------------------------------------------------
// Send DCL to all devices
*}
result := QAPIExtSpecial(handle, JOB_DCL, 1, NULL);
if ( result = 0 ) then
begin
writeln('Command DCL failed\n');
end;
{* Send LLO to all devices *}
result := QAPIExtSpecial(handle, JOB_LLO, 1, NULL);
if ( result = 0 ) then
begin
writeln('Command LLO failed\n');
end;
{* Send GET to device 3 *}
result := QAPIExtSpecial(handle, JOB_GET, 3, NULL);
if ( result = 0 ) then
begin
writeln('Command GET failed\n');
end;
{* Send SDC to device 3 *}
result := QAPIExtSpecial(handle, JOB_SDC, 3, NULL);
if ( result = 0 ) then
begin
writeln('Command SDC failed\n');
end;
{* Send GTL to device 3 *}
result := QAPIExtSpecial(handle, JOB_GTL, 3, NULL);
if ( result = 0 ) then
begin
writeln('Command GTL failed\n');
end;
QAPIExtCloseCard(handle);
end.
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