Package org.lsst.ccs.drivers.parker

Allows communication with a Parker Hannifin ACR-class motor controller over Ethernet.

See: Description

Class Summary

Class	Description
AcrComm	Communicates with a Parker ACR-type motor controller via Ethernet.
TestAcrComm	Provides commands to exercise the AcrComm class from the stand-alone command shell org.lsst.ccs.shell.JLineShell.

Enum Summary

Enum	Description
AxisBit	Names and numbers the some controller bits associated with particular axes.
AxisLong	Defines names and numbers for axis parameters that are signed LONGs.
AxisName	Defines names for eight of the 16 possible axes.
AxisSingle	Defines names and numbers for some axis parameters that are of type FP32.
AxisUnsigned	Defines names and numbers for axis parameters that are unsigned LONGs.
CaptureTrigger	Names and numbers some of the sources of sample triggering signals used for the INTCAP controller command.
ConnectionName	Names and numbers the external connections used to communicate with the controller.
ConnectionUnsigned	Names and numbers the parameters associated with a given communications connection to the controller.
ControllerType	Contains all supported Parker ACR-like controller types.
EncoderLong	Defines names and numbers for some signed LONG encoder parameters.
EncoderName	Defines names for eight out of 16 possible encoders.
LocalDouble	Define names and numbers for some local program variables of type FP64.
LocalDoubleArray	Define names and numbers for some local program arrays of type FP64.
LocalLong	Define names and numbers for some local program variables of type LONG.
LocalLongArray	Define names and numbers for some local program arrays of type LONG.
LocalSingle	Define names and numbers for some local program variables of type FP32.
LocalSingleArray	Define names and numbers for some local program arrays of type FP32.
LocalString	Define names and numbers for some local program string variables.
LocalStringArray	Define names and numbers for some local program string arrays.
MasterBit	Names and numbers controller bits associated with particular masters.
MasterName	Provides names for eight of the 16 possible ACR masters.
MasterUnsigned	Names and numbers some parameters associated with particular masters.
ProgramBit	Names and numbers controller bits associated with particular programs.
ProgramName	Defines names for eight of the possible 16 AcroBasic programs.
ProgramUnsigned	Names and numbers the unsigned long controller parameters associated with particular programs.
SystemBit	Defines names and numbers for some system bits, that is, bits not associated with a master, axis, program or encoder.
SystemUnsigned	Defines the names and numbers used for some LONG motor controller system parameters, that is, unsigned 32-bit parameters not associated with any particular program, axis, master or encoder.
UserParameter	Define names and numbers for some of the global user parameters.

Exception Summary

Exception	Description
AcrComm.Exception	Inner exception class for laundering non-runtime exceptions.

Package org.lsst.ccs.drivers.parker Description

Allows communication with a Parker Hannifin ACR-class motor controller over Ethernet.

Parker's ACR-class controllers can communicate over old-fashioned COM ports, USB or Ethernet. This driver package uses Ethernet, so you must either be prepared to use the factory-standard IP address of 192.168.10.40 or set up your own IP address using one of the other methods of communication. For an ACR9000 we had trouble getting the COM port to work, apparently due to cabling problems. Using USB in combination with Parker's ACR View program worked well.

Once you have the IP address set you can connect to the controller on two basic TCP ports. Port 5002 just takes straight ASCII commands; you can connect to it via telnet and just type away. This package uses port 5006, the combined binary/ASCII command port. Binary commands and their replies are of known lengths and start with a marker byte containing either 0x00 or 0x1d. Binary commands let you fetch parameters and program variables in a binary form that needs little conversion. A transmission starting with a byte other than one of the marker values is treated as straight ASCII save that it must be zero-padded to a multiple of four bytes. Replies to ASCII commands are of variable length and we rely on a timeout to tell us when the reply has ended.

The controller has hundreds of different parameters that can be classified by data type and by which controller object they belong to (if any). The data types are:

• Long - a 32-bit integer. Depending on the parameter it may be signed or unsigned, though for AcroBasic variables it's always signed. This driver uses Java longs to hold these values, sign-extending them if appropriate.
• FP32 - a.k.a Single, a 32-bit floating point value in whatever format the the controller uses internal, which varies among models. A binary fetch of an FP32 value returns it converted to IEEE single precision format. The driver uses Java doubles to hold these values.
• FP64 - a.k.a. Double, a 64-bit floating point value in some model-dependent format. A binary fetch of an FP64 value returns it converted to IEEE single precision. Only the User parameters (see below) and AcroBasic program variables may have this type.

In addition to parameters there are bit flags, which are also divided into groups based on the controller object they control or describe. This driver represents a set bit as true and a clear bit as false.

These are the categories into which parameters and flags are divided:

• User - set aside for the application to which to controller will be put.
• Program - related to one of the AcroBasic programs the controller can store and run.
• Master - related to one of the axis-control masters.
• Axis -related to one of the motion axes (motor+encoder+driver).
• Encoder - related to one of the motor position encoders.
• Connection - one of the controller's means of communication with the user.
• System - general controller operations not tied to one of the object types above.

This package contains enumeration classes giving names to subsets of the controller objects: 32 user parameters, eight programs, eight masters, eight axes, eight encoders and eight connections. For example, the class AxisName contains the names for the axes. Some of the objects named by these classes may not be implemented in your controller.

There are also enumeration classes for various parameters and bits where each class handles one combination of data type and controller object type. There are hundreds of parameters and bits; what we've selected here are the ones which turned out to be useful for the camera shutter but others can be added. Each enumerator will in general have two instance methods: index() which gives the numerical index the controller uses for the parameter/bit and reference() which gives the string used to refer to the parameter/bit in AcroBasic code. These methods will require an object name as argument for parameters/bits that are tied to specific controller objects. For example AxisSingle.JOG_VELOCITY_SETTING.index(AxisName.AXIS0) returns 12348 while AxisSingle.JOG_VELOCITY_SETTING.reference(AxisName.AXIS0) returns "P12348".

There are similar enumerations, such as LocalDouble for a certain number of AcroBasic variables local to controller programs, made possible by the rigid naming scheme employed by the AcroBasic interpreter. See the description of class AcrComm for a description of how variables are named.

A set of methods in AcrComm named simply get() or set() allow you to get and set (if not read-only) all the enumerated parameters, bits and local program variables. Since each enumeration belongs to a specific class, method overloading allows the Java compiler to select the implementation that uses the correct binary command and data encoding. If applicable the method takes an axis, master, program, etc., name in addition to the name of the parameter/bit/variable.