IBLINES

Board-Level

Purpose

Return the status of the eight GPIB control lines.

Format

C

Interactive Control (Usage Notes)

Input

Output

Description

iblines returns the state of the GPIB control lines in clines. The low-order byte (bits 0 through 7) of clines contains a mask indicating the capability of the GPIB interface to sense the status of each GPIB control line. The upper byte (bits 8 through 15) contains the GPIB control line state information. The following is a pattern of each byte.

To determine if a GPIB control line is asserted, first check the appropriate bit in the lower byte to determine if the line can be monitored. If the line can be monitored (indicated by a 1 in the appropriate bit position), check the corresponding bit in the upper byte. If the bit is set (1), the corresponding control line is asserted. If the bit is clear (0), the control line is unasserted.

Example

short lines;
iblines (ud, &lines);
if (lines & ValidREN) {  
   /* check to see if REN is asserted */
   if (lines & BusREN) {
      printf ("REN is asserted");
   }
}

Possible Errors