Chapter 8 wibconf-Windows Interface Bus Configuration Utility
© National Instruments Corp. 8-9 NI-488.2 User Manual for Windows
Send EOI at End of Write
Some devices, as Listeners, require that the Talker terminate a data message by asserting
the EOI line with the last byte. A yes response causes the GPIB board to assert the EOI
line on the last data byte. The default option for this characteristic is yes.
System Controller (Board Characteristic Only)
This field appears on the board characteristics screen only. The System Controller in a
GPIB system is the device that maintains ultimate control over the bus. In some
situations, such as a network of computers linked by the GPIB, another device may be
System Controller and the GPIB board should be designated as not System Controller. A
no response would designate not System Controller and a yes response would designate
System Controller capability. The GPIB board is usually designated as System
Controller. The default option for this characteristic is yes.
Note:You should not have more than one designated System Controller in any GPIB
system.
Assert REN when SC (Board Characteristic Only)
A yes response to this field causes Remote Enable (REN) to be asserted automatically
whenever the board is placed online, if that the board has System Controller capability.
If you give a no response, an explicit call to ibsre is required to assert REN. The
default option for this characteristic is no.
Enable Auto Serial Polling (Board Characteristic Only)
This option enables or disables automatic serial polls of devices when the GPIB Service
Request (SRQ) line is asserted. Positive poll responses are stored following the polls and
can be read with the ibrsp device function. Normally, this feature does not conflict
with devices that conform to the IEEE 488.1 specification. If a conflict exists with a
device, use a no response for this field to disable this feature. The default option for this
characteristic is yes .
Enable CIC Protocol (Board Characteristic Only)
If a device-level NI-488 function is called after control has been passed to another device,
enabling this protocol causes the board to assert SRQ with a Serial Poll status byte of
hex 42. The current Controller must recognize that the board wants to regain control. If
the current Controller passes control back to the board, the device call proceeds as
intended. If control is not passed within the timeout period, or if the CIC protocol is
disabled, the ECIC error is returned. The default option for this characteristic is no .