The lcec_el7041 driver supports
Bekchoff’s EL7041 EtherCAT stepper
driver as well as a couple close relatives. There is also a
lcec_el70x1 driver that overlaps somewhat. These two drivers will
probably be unified in the near future.
To use an EL7041, you will need to add a line to your ethercat.xml file to tell LinuxCNC about the module. This should look like this:
<masters>
<master idx="0" appTimePeriod="1000000" refClockSyncCycles="1000">
...
<slave idx="5" type="EL7041" name="X"/>
...
</master>
</masters>
The index number (5, above) needs to match the slave ID of your
EL7041; run ethercat slaves if you don’t know its ID. The name
provided (X here) has no special meaning, but it’s used in your
LinuxCNC hal config to refer to the stepper, so it’s generally a
good practice to use the name of whichever axis this stepper controls.
In addition, the EL7041 has a number of configuration settings that can be controlled via the XML file. See Beckhoff’s PDF documentation for the EL70x1 family for more in-depth information about each setting.
You can control these by adding <modParam> settings under the EL7041’s <slave> entry:
<masters>
<master idx="0" appTimePeriod="1000000" refClockSyncCycles="1000">
...
<slave idx="5" type="EL7041" name="X">
<modParam name="maxCurrent" value="2.5"/>
<modParam name="nominalVoltage" value="48"/>
</slave>
...
</master>
</masters>
Notice that instead of <slave ... />, we now have <slave ... >
... </slave>, without the trailing / on the first <slave/> tag.
Each <modParam/> line has a name="..." and a value="..." setting.
Supported parameters:
maxCurrent: the maximum current for the stepper. In Amps. Default depends on the device, EL7041 defaults to 5.0A.reducedCurrent: reduced current for reduced torque. In Amps. EL7041 defaults to 2.5A. (Unsupported on EL7041-1000)nominalVoltage: the nominal voltage of the motor, in Volts. EL7041 defaults to 50.0VcoilResistance: the internal resistance of a motol coil, in Ohms. EL7041 defaults to 1.0 Ohm. (Unsupported on EL7041-1000)motorEMF: Motor countervoltage, in V/(rad/S). Defaults to 0. (Unsupported on EL7041-1000)motorFullsteps: number of motor steps per full revolution. Defaults to 200.encoderIncrements: number of encoder increments per revolution.startVelocity: Maximum possible start velocity of the motor. Unit unknown, default varies.driveOnDelay: Switch-on delay of the driver stage, in ms. Defaults to 100ms.driveOffDelay: Switch-off delay of the driver stage, in ms. Defaults to 150ms.maxSpeed: maximum supported speed in full steps/second. 1000, 2000, 4000, 8000, 16000, or 32000. (Unsupported on EL7041-1000)encoder: true if an encoder is connected. The EL7041 will report “fake” encoder data if this is not set.microsteps: Number of microsteps used. Valid values are 1, 2, 4, 8, 16, 32, or 64. (Only supported on EL7041-1000)Note that not all hardware will support all of these parameters.
Attempting to set a parameter that the hardware does not support will
cause LinuxCNC to fail to start and report an error message. Check
ethercat sdos to see which SDOs your hardware supports.
See gitub.com/linuxcnc-ethercat/linuxcnc-ethercat for view existing bugs and file new issues.