Summary of I/O Operations Summary of I/O Operations The following table summarizes the eV+ I/O instructions: System Input/Output Operations eV+Language User's Guide, v2.x, 18318-000 Rev A Page 157 Keyword Type Function ATTACH PI Make a device available for use by the application program. BITS PI Set or clear a group of digital signals based on a value. BITS RF Read multiple digital signals and return the value corresponding to the binary bit pattern present on the signals. $DEFAULT SF Return a string containing the current system default device, unit, and directory path for disk file access.
DEF.DIO PI Assign third-party digital I/O boards to standard eV+ signal numbers, for use by standard eV+ instructions, functions, and monitor commands.This instruction requires the Third- Party Board Support license. DETACH PI Release a specified device from the control of the application program. DEVICE PI Send a command or data to an external device and, optionally, return data back to the program. (The actual operation performed depends on the device referenced.) DEVICE RF Return a real value from a specified device. The value may be data or status information, depending upon the device and the parameters. DEVICES PI Send commands or data to an external device and optionally return data.
The actual operation performed depends on the device referenced. FCLOSE PI Close the disk file, graphics window, or graphics icon currently open on the specified logical unit. FCMND PI Generate a device-specific command to the input/output device specified by the logical unit.