NAME

hpib_rqst_srvce() − allow interface to enable SRQ line on HP-IB

SYNOPSIS

#include <dvio.h>

int hpib_rqst_srvce(int eid, int cv);

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:

[EBADF] eid does not refer to an open file. 

[ENOTTY] eid does not refer to an HP-IB raw bus device file. 

[ETIMEDOUT] a timeout occurred. 

[EACCES] The interface associated with this eid is locked by another process and O_NDELAY is set for this eid (see io_lock(3I)). 

DEPENDENCIES

Series 300/400:

The HP98625A/B and HP25560A HP-IB interface cards allow only bit 6 to be set.  All other bits are cleared. 

EIO is returned if a timeout occurs. 

Series 800:

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. 

Hewlett-Packard Company  —  HP-UX Release 9.0: August 1992