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The purpose of this page is to describe changes to update your configuration files to work with a newer version of emc.

Always back up your working configuration before making changes to it toc

For configurations that have not customized emc.nml, remove the inifile line NML_FILE = emc.nml. This will cause the most up to date version of emc.nml to be used.

For configurations that have customized emc.nml, a change similar to this one is required.

Failure to do this can cause an error like "libnml/buffer/physmem.cc 143: PHYSMEM_HANDLE: Can't write 10748 bytes at offset 60 from buffer of size 10208."

The format of the tool table has been changed incompatibly. The documentation shows the new format. The tool table will automatically be converted to the new format.

The hostmot2 firmware images are now a separate package. You can:

• continue using an already-installed emc2-firmware-mesa-* 2.3.x package
• install the new packages from the package server. the new packages are named hostmot2-firmware-*
• download the firmware images as tar files from http://emergent.unpy.net/01267622561 and install them manually

hal_joystick was deprecated since emc2.2, did not work at all in 2.4.0, and was removed in 2.4.1. Use hal_input instead. There is no direct conversion from hal_joystick to hal_input because of the wide variety of names hal_input can give to devices, but all devices supported by the former are supported by the latter.

Because tool offsets can be applied on all 9 axes, the old pin halui.tool.length_offset has been removed. For the Z tool length offset, use halui.tool.length_offset.z instead.

In 2.3, you must home all axes before issuing MDI commands or running part programs. This setting can be reverted to the 2.2 behavior by the inifile setting [TRAJ]NO_FORCE_HOMING = 1. For users of the mini GUI, this setting may be required.

The transitional drivers m7i43_hm2, mesa7i43_gpio and hm2_5i20 are withdrawn. Use the new hostmot2 driver instead. (use hm2_pci for 5i20 cards).

hal_m5i20 will remain in 2.3, but will be removed in 2.4.

There are now separate firmware packages for each type of hostmot2 supported hardware. Depending on the hardware you own, select and install the appropriate firmware package (e.g., emc2-firmware-mesa-5i20-hostmot2)

The declaration "license" is now mandatory. It should specify a source code license in the form accepted by the Linux kernel for taint checks. e.g.,: license "GPL";

The pins, parameters, and function have been renamed to better follow the common naming convention. See the manpage for information about the new names: http://linuxcnc.org/docs/2.3/html/man/man9/timedelay.9.html

• The number of physical input and output pins default to 15 each ( it was 50 before). The idea is less clutter and most of the time people set these to what they want anyways.
  
• Classicladder now uses %IW and %QW variables to connect to s32in and out pins instead of mapping them onto %W variables.
  The default number of s32 in and out pins is now 10 each.
  Ladder programs would need to be changed if they use s32 pins.
  
• Old timers will use a new control pin. To make it work as before connect the C pin to the E pin.
  
• default number of bits is now 20 (from 500)
  
• default number of words is now 10 (from 100)
  

Change any use of 'motion.motion-inpos' to 'motion.in-position'.

In 2.2.x hm2 gpio pins had HAL names that included the connector name. In 2.3.x this was changed to "hm2_<BoardType>.<BoardNum>.gpio.<IONum>". IONum is a three-digit number. The mapping from IONum to connector and pin-on-that-connector is written to the syslog when the driver loads, and it�s documented in Mesa�s manual for the Anything I/O boards.

The m5i20 "encoder" pins now match the HAL canonical encoder interface. The -cnt-latch, -pos-latch, -idx-latch, and -latch-index pins have been removed. The standard encoder pin -index-enable has been added. The behavior of the -position and -count pins now match the HAL canonical interface.

Most pins and parameters on pluto-servo were changed to use dots instead of dashes, in accordance with the HAL canonical naming conventions. For example, 'pluto-servo.encoder-0-velocity' has been renamed to 'pluto-servo.encoder.0.velocity' and 'pluto-servo.dout-00-invert' has been renamed to 'pluto-servo.dout.00-invert'.

The units for steplen, stepspace, dirsetup, and dirhold have been changed from BASE_PERIOD units to nanosecond units. Internally, the values given are rounded up to a multiple of BASE_PERIOD, and at runtime the parameters are changed to display the rounded up value.

Freqgen has been deprecated and replaced by stepgen, which now has an additional command line argument 'ctrl_mode', which can be used to specify position mode (the default) or velocity mode. Position mode is the default, and works the same as before. Velocity mode accepts a velocity command, and works like freqgen.

In step modes 0 and 1, setting stepspace to 0 will allow "step" (or "up/down") to be asserted on every invocation of make-pulses. Use a stepspace value of 1 to signify "the smallest nonzero stepspace".

halcmd and hal_link() now refuse to link an already-linked pin. This immediately diagnoses configuration errors of the form net limit-switch parport.0.pin-26-in => axis.0.neg-lim-sw-in axis.0.pos-lim-sw-in net home-switch parport.0.pin-26-in => axis.0.home-sw-in which have the effect of leaving no pin driving the limit switch inputs. If the "re-link" behavior is truly desired, add "unlinkp" commands before the new link. It is still permitted for "unlinkp" to be used on an unconnected pin.

The 'counter' component is deprecated. For a one-phase, unidirectional counter, use the 'encoder' component with encoder.X.counter-mode=TRUE. The version in 'encoder' has superior velocity estimation.

The homing algorithm has been changed to be "level sensitive" instead of "edge sensitive". This eliminates some possible "miss the switch and go to the end of travel" errors on machines with flakey switches. However, it will cause homing to fail on some machines that might have worked before. This can happen if the following conditions are true:

1.The home switch does not remain on from the point that it trips till the end of axis travel 2.Homing speed is high and/or decel rate is low, so that the machine will overshoot the switch when it hits it during homing.

If the machine ends up on the far side of the switch during homing, it will stop with an error message.

Machines that can wind up "on the far side" of the home switch are considered to have defective switches. If you ever attempt to home while on the wrong side of the switch, it will run to the end of the axis. There is NO possible software solution to that scenario - the proper solution is a home switch that remains on all the way to the end of the axis. With such a switch, EMC-2's homing algorithm will always work.

The new pin motion.spindle-speed-in must be connected for Feed Per Revolution (G95) to work. The value connected must be a revolutions per second value. Depending on the machine, this can be a feedback velocity from the encoder or a commanded velocity loopback. If using a loopback, the output value which is in revolutions per minute must be multiplied by .0167 with a gain component to convert to RPS.

Additional error checking is now done in halcmd, so that giving too many arguments causes an error message to be printed. In 2.1 and earlier, these extra arguments were ignored.

Note that this is the number of arguments that are present after the expansion of inifile references, such as setp example.scale [AXIS_0]INPUT_SCALE which might expand to to setp example.scale 32000 0 in this case, the fix is to modify the inifile to remove the second number "0" from the INPUT_SCALE. This second value is no longer used anywhere in emc2.

The .var file has been extended to require coordinate system offsets for U, V and W axes. In version 2.2.1 and above, the required additions to the .var file are automatically made, and no user intervention is required.

when loading classicladder user program, only load it once with or without --nogui option. loading it twice will cause the symbols window to not work properly, though the ladder program will run fine.

There is an [experimental script] for automatic conversion of emc2.0 configuration files. It fixes items 1, 2, 3, 8, and 9 below.

The emc.nml file has been heavily revised. Unless you made your own changes to emc.nml, simply make a fresh copy. If you made your own changes, then you'll have to apply them to emc.nml manually. The diff is [here]

Now a separate kinematics module must be loaded before MOTMOD, as shown in [this diff].

The HAL pins for spindle control have been renamed to reflect the fact that they are controlled by the realtime 'motion' component, and not by the userspace 'iocontrol' component, as shown in [this diff].

In 2.0 there was no way to wait for a userspace component to create its pins. The "wait-for-pin" program (which took a pin name as an argument) was added and then removed during the 2.1 development cycle. Now, the correct way to wait for a userspace component is "loadusr -W ...". This requires that the component call hal_ready() after it has created all its pins and is ready for use. If the executable name and the component name differ, use "halcmd loadusr -W -n component-name".

[Replacement of 'sleep' with 'loadusr -W']

[Replacement of 'wait-for-pin' with 'loadusr -W'; use of 'loaduser -Wn']

Instead of specifying [AXIS_]UNITS as a decimal number, specify [TRAJ]LINEAR_UNITS and [TRAJ]ANGULAR_UNITS as unit names, including "inch", "mm", "degree", and "radian". The old [AXIS_]UNITS syntax is still supported, however. [diff]

In emc 2.1, a new tool called "[comp]" makes it easy to create HAL components. All the items that are in the 'blocks' module have been broken into separate modules such as 'ddt', 'wcomp', and so on.

No corrective action is needed at this time, because 'blocks' will still be present in the 2.1 series. However, it may be removed in the 2.2 series, and changes to HAL files will be required at that time.

If you wish to silence this warning, then change a line like loadrt blocks ddt=6 wcomp=6 to loadrt ddt count=6 loadrt wcomp count=6

[Replacement of 'blocks' with individual components]

In version 2.0.x, many HAL components would accept a command line argument "period" (or "periodfp", or other variations on that theme). When "period" was specified, the component would create a realtime thread running at the specified period. This capability was not used in normal EMC configurations; it was mostly used for testing. (In a normal EMC configuration, the servo and base periods are passed to motmod and it creates the threads.)

In version 2.1, the period argument has been removed from all HAL components. 'motmod' still creates the threads for EMC, and none of the sample configurations should need to be changed. For other applications such as testing, etc., there is now a component called "threads" which can create up to three threads. To create a thread, use "loadrt threads name1=<name-of-thread> period1=<period-in-ns>". To create more than one, use name2, period2, and name3, period3. By default, "threads" creates floating point capable threads. If you don't need floating point, you can specify "fp1=0" (or fp2=0 or fp3=0) to turn off floating point support for one or more threads. Disabling floating point support might save a microsecond or so, and is commonly done for the "fast" thread for software encoder counting and step pulse or PWM generation.

The number of HAL types has been reduced. "newsig" commands which formerly used one of those types should be converted to the corresponding 32-bit type, s32 or u32.

Instead of being specified in units of 100ns, these values (now named setup-time-ns, etc) are in units of 1ns. [Changes to the sample USC configuration file]

The name of the pin used for indexing (homing to index pulse) has been changed to be more descriptive. [Changes to the sample motenc configuration file]

In emc 2.0.x, the output of the comparator would not change until the difference between the inputs exceeded the hysteresis parameter, giving an effective hysteresis of double the parameter. Now, the output will change when the difference exceeds hyst/2. This more closely matches the [usual definition of hysteresis]. Existing users of the 'comp' block must change (double) the value of the 'comp.N.hyst' parameter. [Changes to the sample sim configuration file]

In the preliminary lathe threading support in 2.0 versions, a "not" block was needed to connect the motion controller to the spindle encoder's index-enable pin. This is no longer necessary (and will not work). [changes to the sim/lathe.hal file]