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NAME

wait - synchronization with moving, counting and other activity

SYNOPSIS

wait(mode)

DESCRIPTION

The function wait() is used to synchronize the flow of commands in spec with moving, counting and other activity. Since the built-in commands and functions move_all, move_cnt, tcount() and mcount() return immediately after starting moving or counting, macros need to include some form of wait() if the next command requires the previous move or count to complete.

The argument mode specifies what is to be waited for:

0 - moving, counting and other acquisition
1 - (bit 0) moving
2 - (bit 1) counting (by the master timer)
4 - (bit 2) other acquisition (MCAs, CCDs, etc.)
8 - (bit 3) remote connections and remote asynchronous events
32 - (bit 5) return zero or nonzero to indicate if busy

If mode is a negative number, wait() will behave as for mode = 0, but a message will be printed showing what is being waited on.

When spec is running as client to a spec server, bit 3 checks if remote_async() replies have all arrived. In addition, bit 3 also checks if all configured spec servers have connected and if all spec server and EPICS remote motors have connected.

Waiting for spec server and remote motor connections is mainly an issue on start up or after reconfig. One might use wait(8) or wait(0x28) in the built-in special macro config_mac if it is important to delay until all connections are up. Note, until remote spec server and EPICS motors are fully connected and usable, the positions reported for those motors will be the last saved positions from spec's settings file.

Also, note that wait(0) does not check for the remote events flagged by bit 3. To wait for remote events requires explicitly setting bit 3 in mode. Also, a ^C interrupts a wait(8) but doesn't change the conditions that caused wait(8) to block. That is, the next wait(8) will still block if there are still pending connections.

If bit 5 (0x20) in mode is set, wait() returns true (1) if the activities flagged by bits 0, 1, 2 or 3 are still going on, otherwise wait() returns false (0).

EXAMPLES

def waitall   'wait(0)'


def waitmove  'wait(1)'


def waitcount 'wait(2)'


def w   'wait(0); beep'

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