org.lsst.ccs.subsystem.shutter.plc

Class Tools

java.lang.Object

org.lsst.ccs.subsystem.shutter.plc.Tools

public class Tools
extends Object

Provides some small utility functions.

Author:

tether

Constructor Summary

Constructors

Constructor and Description
Tools()

Method Summary

Modifier and Type	Method and Description
static Duration	fromDcDuration(long dcNanos) Converts EtherCat time interval, assumed to be the difference of two DC time values, into a Duration.
static org.lsst.ccs.utilities.taitime.CCSTimeStamp	fromDcInstant(long dcNanos) Converts an EtherCAT Distributed Clock time value into a CCS timestamp with millisecond precision.
static boolean	getBoolean(ByteBuffer data) Gets a PLC BOOL value from a byte buffer and converts it to a boolean value.
static void	main(String[] args)
static void	putBoolean(ByteBuffer data, boolean b) Appends to a byte buffer the PLC BOOL value equivalent to a Java boolean.
static long	toDcDuration(Duration interval) Reverses the transformation performed by toDcDuration(java.time.Duration).
static long	toDcInstant(org.lsst.ccs.utilities.taitime.CCSTimeStamp stamp) Converts a CCS timestamp to a DC time value (count of nanoseconds) with millisecond resolution.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Tools

public Tools()

Method Detail

getBoolean

public static boolean getBoolean(ByteBuffer data)

Gets a PLC BOOL value from a byte buffer and converts it to a boolean value.

Parameters:

data - Holds the data.

Returns:

The boolean value.

putBoolean

public static void putBoolean(ByteBuffer data,
                              boolean b)

Appends to a byte buffer the PLC BOOL value equivalent to a Java boolean.

Parameters:

data - Holds the data.

b - The boolean value to convert and append.

fromDcInstant

public static org.lsst.ccs.utilities.taitime.CCSTimeStamp fromDcInstant(long dcNanos)

Converts an EtherCAT Distributed Clock time value into a CCS timestamp with millisecond precision.

Assuming that the DC time is being kept in sync with a TAI or GPS time source then it's just a question of adjusting the epoch from that of DC time, 01-01-2000T00:00:00 UTC, to that of Unix, 01-01-1970T00:00:00 UTC. We do that by adding 946,684,813,000 milliseconds.

Parameters:

dcNanos - The DC time value measured in nanoseconds since 01-01-2000T00:00:00 UTC.

Returns:

The CCS timestamp obtained from CCSTimeStamp.currentTimeFromMillis().

toDcInstant

public static long toDcInstant(org.lsst.ccs.utilities.taitime.CCSTimeStamp stamp)

Converts a CCS timestamp to a DC time value (count of nanoseconds) with millisecond resolution.

Parameters:

stamp - The CCS timestamp.

Returns:

The number of nanoseconds since the DC time epoch, see fromDcInstant(long).

fromDcDuration

public static Duration fromDcDuration(long dcNanos)

Converts EtherCat time interval, assumed to be the difference of two DC time values, into a Duration.

Parameters:

dcNanos - The DC time difference, a count of nanoseconds.

Returns:

The Duration value.

toDcDuration

public static long toDcDuration(Duration interval)

Reverses the transformation performed by toDcDuration(java.time.Duration).

Parameters:

interval - The time interval to convert.

Returns:

The count of nanoseconds.

main

public static void main(String[] args)