NEWS
LinuxCNC 2.5.2 Release
There are no translations available.

LinuxCNC 2.5.2 Update Released (changelog).
 
LinuxCNC 2.5.1 Release
There are no translations available.

LinuxCNC 2.5.1 Update Released (changelog). If the Package Manager does not prompt you to upgrade see this page.

 
LinuxCNC 2.5.0 Release
There are no translations available.

New major release (changelog). See the instructions to update your system from EMC 2.4 to LinuxCNC 2.5.
 
Home Forum Configuring LinuxCNC PnCConf Wizard Mesa 5i20 - 7i37TA - 7i48

Welcome, Guest
Username: Password: Remember me

TOPIC: Mesa 5i20 - 7i37TA - 7i48

Re:Mesa 5i20 - 7i37TA - 7i48 08 Apr 2012 18:47 #19036

Funny you should mention encoders. Now that I have the i/o working I checked to see if the encoders were working. Y is working perfectly. X and Z show some movement (thous or tenths) when I manually turn the screws. I've checked that the encoders have +5VDC where they should.
The administrator has disabled public write access.

Re:Mesa 5i20 - 7i37TA - 7i48 08 Apr 2012 19:06 #19037

  • PCW
  • PCW's Avatar
  • OFFLINE
  • Moderator
  • Posts: 1649
  • Thank you received: 86
  • Karma: 116
For debugging encoders, first thing to look at is the rawcounts pin (with halmeter)
if it only toggles back and forth one count, this indicates that one of the A/B signals
is not getting to the counter.

If rawcount counts up and down, but the DRO is wrong, then you likely have a scaling problem
The administrator has disabled public write access.

Re:Mesa 5i20 - 7i37TA - 7i48 09 Apr 2012 11:37 #19054

x and z rawcounts only toggle back and forth one count as you describe. bad encoders or wiring issue? anyway i can check at the encoder? i dont have a scope.
The administrator has disabled public write access.

Re:Mesa 5i20 - 7i37TA - 7i48 09 Apr 2012 11:48 #19056

  • PCW
  • PCW's Avatar
  • OFFLINE
  • Moderator
  • Posts: 1649
  • Thank you received: 86
  • Karma: 116
Are the encoders single ended or differential?
that is, is there a single A,B and perhaps Z wire or are there a Pair for each? (A,/A B, /B and Z, /Z)

The encoder signals can be checked with a voltmeter or perhaps more easlily with a LED and a resistor

For single ended signals the LED anode should connect to 5V through a say 300 Ohm resistor and the cathode to the encoder signal

For differential encoders the LED+resistor should be connected between the A and /A or B and /B signals

Both the A and B signals should toggle when the shaft is turned slowly
The administrator has disabled public write access.

Re:Mesa 5i20 - 7i37TA - 7i48 09 Apr 2012 14:26 #19063

I measured voltage from A+ to A- and B+ to B- at the encoder connector on the X and Z encoders. Unfortunately the Y encoder does not have a connector near the encoder. On both encoders the A readings were between 0V and .5V. The B readings on both encoders were between 3.2V and 3.8V. As I turned the screws the readings move around in those ranges. I tried the LED as well (before trying the multimeter). As expected A wouldnt light the LED and B lit it dimly.
The administrator has disabled public write access.

Re:Mesa 5i20 - 7i37TA - 7i48 09 Apr 2012 15:15 #19068

  • PCW
  • PCW's Avatar
  • OFFLINE
  • Moderator
  • Posts: 1649
  • Thank you received: 86
  • Karma: 116
The A pair and the B pair should behave identically , that is
all pins should have roughly TTL level swings
(with a 0-.4V low and a 2.4 to 5V high)
depending on shaft position
if the A and B pairs behave differently I would check your wiring
The administrator has disabled public write access.
Moderators: cmorley
Time to create page: 1.385 seconds
Powered by Kunena Forum
© 2013 LinuxCNC.org
Joomla! is Free Software released under the GNU General Public License.