HPIB_SPOLL(3D)
NAME
hpib_spoll − conduct a serial poll on HP-IB bus
SYNOPSIS
int hpib_spoll (eid, ba);
int eid, ba;
HP-UX COMPATIBILITY
Level: Device I/O Library − HP-UX/EXTENDED
Origin: HP
DESCRIPTION
Hpib_spoll conducts a serial poll of the specified device. Eid is an entity identifier of an open HP-IB raw bus device file obtained from an open(2), dup(2), fcntl(2), or creat(2) call. Ba is the bus address of the intended device.
Hpib_spoll polls a single device for its response byte. The information stored in the response byte is device specific with the exception of bit 6. If bit 6 of the response byte is set, the addressed device has asserted the SRQ line, and is requesting service. (Note that the least significant (right-most) bit of the response byte is bit 0.)
Not all devices respond to the serial poll function. Consult the device documentation. Specifying a device that does not support serial polling may cause a timeout error or suspend your program indefinitely (see hpib_rqst_srvce(3)). The interface cannot serial poll itself. The interface must be the active controller.
RETURN VALUE
If hpib_spoll is successful, the device response byte is returned in the least significant byte of the return value. Otherwise, −1 is returned, indicating an error.
SEE ALSO
DIAGNOSTICS
Hpib_spoll fails under the following circumstances, and sets errno (see errno(2)) to the value in square brackets:
eid does not refer to an open file [EBADF];
eid does not refer to an HP-IB raw bus device file [ENOTTY];
the device polled did not respond before timeout, or the interface is not the active controller [EIO];
ba is the address of the polling interface itself [EINVAL].
Hewlett-Packard — last mod. May 11, 2021