National Instruments GPIB-PC - page 113

BASICA/QuickBASIC GPIB-PC Function Calls Section Four A
GPIB-PC User Manual 4A-38 ©National Instruments Corp.
BASICA/QuickBASIC BASICA/QuickBASIC
IBLOC IBLOC
Purpose: Go to Local
Format: CALL IBLOC (BD%)
Remarks: BD% specifies a device or an interface board.
Unless the Remote Enable line has been unasserted with
the IBSRE function, all device functions automatically
place the specified device in remote program mode.
IBLOC is used to move devices temporarily from a remote
program mode to a local mode until the next device
function is executed on that device.
Device IBLOC Function:
IBLOC places the device indicated in local mode by calling IBCMD to
send the command sequence:
• Unlisten (UNL);
• Listen address of the device;
• Secondary address of the device, if necessary;
• Go To Local (GTL); and
• Untalk (UNT) and Unlisten (UNL).
Other command bytes may be sent as necessary.
On exit, all devices are unaddressed.
Board IBLOC Function:
When BD% specifies an interface board, the board is placed in a local
state by sending the local Return To Local (rtl) message, provided it is
not locked in remote mode. The LOK bit of the status word indicates
whether the board is in a lockout state. The IBLOC function is used to
simulate a front panel Return To Local switch when the computer is
used as an instrument.