hpib_rqst_srvce(3I)

DESCRIPTION

hpib_rqst_srvce() specifies a response byte to be sent by the interface when it is serially polled by the active controller. eid is an entity identifier of an open HP-IB raw bus device file obtained from an open(), dup(), fcntl(), or creat() call. cv is an integer control value representation of the desired response byte.

hpib_rqst_srvce() optionally enables the SRQ line depending upon the response byte. If bit 6 of the response byte is set, the SRQ line is enabled. It remains enabled until the active controller conducts a serial poll or until the computer executes the request function with bit 6 cleared. However, the SRQ line is not enabled as long as the interface is active controller. If bit 6 is set, the interface remembers its response byte, and enables the SRQ line when control is passed to another device on the bus.

The response byte is structured as follows:

RETURN VALUE

hpib_rqst_srvce() returns 0 (zero) if successful, or -1 if an error was encountered.

ERRORS

hpib_rqst_srvce() fails under the following circumstances, and sets errno (see errno(2)) to the value in square brackets:

DEPENDENCIES

The HP27110B HP-IB interface card allows only bit 6 to be set. All other bits are cleared.

AUTHOR

hpib_rqst_srvce() was developed by HP.