pvsbuffer

pvsbuffer — This opcode creates and writes to a circular buffer for f-signals (streaming PV signals).

Description

This opcode sets up and writes to a circular buffer of length ilen (secs), giving a handle for the buffer and a time pointer, which holds the current write position (also in seconds). It can be used with one or more pvsbufread opcodes. Writing is circular, wrapping around at the end of the buffer.

Syntax

ihandle, ktime  pvsbuffer fsig, ilen 

Initialisation

ihandle -- handle identifying this particular buffer, which should be passed to a reader opcode.

ilen -- buffer length in seconds.

fsig -- an input pv stream

ktime -- the current time of writing in the buffer

pvsbuffer stores fsig in a buffer which can be read by pvsbufread using the handle ihandle. Different buffers will have different handles so they can be read independently by different pvsbufread opcodes. pvsbuffer gives in its output the current time (ktime) inside the ring buffer which has just been written.

Examples

See pvsbufread for examples of the pvsbuffer opcode.

See also

pvsbufread

Credits

Author: Victor Lazzarini
July 2007