So, my problem started out as being a "limit tripped" in the 7 segment display on the dc310b. Once i got that figurred out now i am getting a "x axis error" in mach 3 but i am still getting encoder readings on my DRO's on my screen. Being its the weekend and the support office is closed, i did some searching on the Mach support website and found a person with a simalar problem.
Axis X encoder error
« on: January 29, 2010, 08:23:00 PM »
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I have my X,Y and Z axis encoders being properly read by Mach3.
I know this because Mach3 correctly displays the coordinates reliably and each shows 0.200" per ball screw rev when turned manually. (even in the right direction).
But I can't get Mach3 to come off Reset, when I click on Reset I get the error 'Axis X encoder error'
Can't find any help on this error, does anyone have any advice?
Thanks
Then after the person talked to Ajax he posted this
Re: Axis X encoder error
« Reply #14 on: February 01, 2010, 11:30:57 AM »
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Looks like the DROs only need A and B channels to operate (/A and /B not used to update DROs).
But, when Reset is clicked, the Mach Ajax Plugin compares at least the A and /A to get a signal level. If that level is below 3V then the error is triggered.
With line driver output encoders this is no problem, however my encoders are SumTak LBL-041-500 5v 160ma open collector outputs.
The Tree325 Dynapath controller did not use the /A, /B or /Z signals and only had 1k pullups on the A, B and Z signals.
The schematic Ajax supplied simply showed to hook up an encoder straight thru with no pullups.
Somehow the DROs updated even without pullups but the High state read only 0.012V and the low was 0.08V.
I attached the 1k pullups and was able to get a High state of 0.88V and a Low of 0.1V.
With 510 ohm pullups I get 1.3V High and 0.2V Low.
The Tree ran for 20 years with no noise problems so I am basically happy using the 510 ohm pullups which gives the MPU11 inputs 7ma in the 1.3V High state.
It looks like the signals go into an AM26LV32, BiCMOS, quadruple, differential line receiver.
The response from Ajax has been very positive and they are willing to provide a Beta version Plugin to me that has a parameter that can be set to turn off the 3V signal check when Reset is clicked.
Does anybody see a problem with this decision? There are a lot of open collector encoders out there as potential upgrades so I hope this is a good way to go.
The line driver encoders specs that i have are below.
TRD-Sxxxx-VD
TRD-SHxxxxVD
(line driver)
Power Supply
Operating Voltage: +4.75 - 5.25VDC*
Current Consumption: 50 mA max.
Signal Waveform: Two-phase + home position
Max. Response Frequency: 200kHz
Duty Ratio: 50 ± 25%
Phase Difference Width: 25 ± 12.5%
Signal Width at Home Position: 100 ± 50%
Output:
Line driver output (26C31 or equivalent)
Output Logic: Negative logic (active high)
Output Current H - 2.5 V min.
Output Voltage L - 0.5 V max.
Short-Circuit Protection Between output and power supply
So, I guess my question is do I need to get some step ups to get my voltage above 3V so i can stop the "x axis error"? If so, what size(510ohm)? Where do they install. close to the encoder or by the plug on the mpu11? Would I only need to install the step ups on the a,a- channels or all of them? Thanks