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I can't find a suitable configuration so that the analog output can control the correct movement of the punching machine's piston. How do I solve this?Summary of what I'm trying to control:The piston that hits the punches is hydraulic, but it has an actuator that controls its descent and ascent by applying analog voltage of -10 volts and +10 volts, where +10 volts goes up and -10 volts goes down. However, unlike a motor, when there is no voltage at all, the piston descends gradually. To keep it high, a voltage above 2 volts positive will always be necessary.Hardware information: the sensor that detects the movement of the piston hitting the punches is magnetic and provides an analog output voltage, being 0 volts when it descends completely and 8 volts when it rises completely. This position voltage is connected to the THCAD2 electronic board that converts it into frequency. This frequency is used in channel 0 of the 7i77 electronic board's encoder, which is configured asThis reading is being shown on the display after the following modificationI'm worried that the problem is becausewas disconnected since it is being used to report the position, will the 7i77 electronic board work without net z-vel-fb?

Below is information that may helpWhen I manually jog the Z axis to 1mm or 5mm, it makes no difference in the actual movement of the piston, it always moves the same and the Z axis calculation error appearsWhen I manually jog the Z axis to 1mm

  When I manually jog the Z axis to 5mm  Piston hitting the punches in the zero position

  Piston hitting the punches in the position after a 1mm jog

 
 Piston hitting the punches in the position after a 5mm jog  I have been working on this machine retrofit for over 2 years, unfortunately here in Brazil I have not found qualified labor to perform this service. If I cannot resolve this step I will have to give up on LinuxCNC. I am willing to pay if someone resolves this situation. Even so, I thank all the contributions from the Forum and Mr. Peter.

Try this:

# ---Encoder feedback signals/setup---

#setp hm2_7i96s.0.encoder.00.counter-mode 0 #Default PNCConf Wizard
setp hm2_7i96s.0.encoder.00.counter-mode 1 #change to accept signal from THCAD2 board as Z axis feedback
#setp hm2_7i96s.0.encoder.00.filter 1 #Default PNCConf Wizard
setp hm2_7i96s.0.encoder.00.filter 0
setp hm2_7i96s.0.encoder.00.index-invert 0
setp hm2_7i96s.0.encoder.00.index-mask 0
setp hm2_7i96s.0.encoder.00.index-mask-invert 0
setp hm2_7i96s.0.encoder.00.scale [JOINT_1]ENCODER_SCALE

net z-pos-fb <= hm2_7i96s.0.encoder.00.velocity

#net z-vel-fb <= hm2_7i96s.0.encoder.00.velocity
net z-pos-fb => joint.1.motor-pos-fb
net z-index-enable joint.1.index-enable <=> hm2_7i96s.0.encoder.00.index-enable
net z-pos-rawcounts <= hm2_7i96s.0.encoder.00.rawcounts

Good afternoon, dear friends.

Please, how should I make the connections in the HAL file so that the 7i77 electronic board accepts the frequency generated by the THCAD2 electronic board as feedback from the Z axis?

Below is the basic code generated by PNCConf from LinuxCNC:

Note:

The TCHAD2 electronic board receives the analog voltage from the Z-axis movement which is a magnetic sensor with repeatability accuracy of 10µm (MICRA, micron or micron), with a recordable speed of 10m/s (meters per second) and IP67 classification (dust protection and water and oil resistance).
This sensor provides 0 volts at the output when the Z axis is lowered and 8 volts at the output when the Z axis is raised. The TCHAD2 electronic board converts this voltage into a frequency of 100kHz to 1Mhz (according to the chosen jumper). Then the 7i77 electronic board receives this frequency on encoder channel 0. It displays the position results counting to infinity, with only velocity being usable as position, with the low Z axis having a low frequency and the high Z axis having a high frequency.
Please, any basic example helps or suggestions. I appreciate your collaboration. Attached is a video showing how the values ​​from the TCHAD2 electronic board are being received by LinuxCNC.

*MICRA: The symbol (µm) and correspond to the microscopic unit of measurement, where 1 micron is the same as dividing 1 millimeter by 1000


 

Hello everyone, I'm back, happy 2025 to all. Please, I need help to return to the retrofit process of a punching machine.
I have the hardware configuration 7i96s + 7i77 + 7i84d and THCAD2
I need to make the 7i77 board work to drive the Z axis with feedback from the THCAD2. To get a basic code example, I used linuxCNC's PNCConf to generate a basic code example.

The basic code generated was:

# ---PWM Generator signals/setup---

setp hm2_7i96s.0.7i77.0.0.analogout0-scalemax [JOINT_1]OUTPUT_SCALE
setp hm2_7i96s.0.7i77.0.0.analogout0-minlim [JOINT_1]OUTPUT_MIN_LIMIT
setp hm2_7i96s.0.7i77.0.0.analogout0-maxlim [JOINT_1]OUTPUT_MAX_LIMIT

net z-output => hm2_7i96s.0.7i77.0.0.analogout0
net z-pos-cmd <= joint.1.motor-pos-cmd
net z-enable <= joint.1.amp-enable-out

# ---Encoder feedback signals/setup---

setp hm2_7i96s.0.encoder.00.counter-mode 0
setp hm2_7i96s.0.encoder.00.filter 1
setp hm2_7i96s.0.encoder.00.index-invert 0
setp hm2_7i96s.0.encoder.00.index-mask 0
setp hm2_7i96s.0.encoder.00.index-mask-invert 0
setp hm2_7i96s.0.encoder.00.scale [JOINT_1]ENCODER_SCALE

net z-pos-fb <= hm2_7i96s.0.encoder.00.position
net z-vel-fb <= hm2_7i96s.0.encoder.00.velocity
net z-pos-fb => joint.1.motor-pos-fb
net z-index-enable joint.1.index-enable <=> hm2_7i96s.0.encoder.00.index-enable
net z-pos-rawcounts <= hm2_7i96s.0.encoder.00.rawcounts

# ---setup home / limit switch signals---

net z-home-sw => joint.1.home-sw-in
net z-neg-limit => joint.1.neg-lim-sw-in
net z-pos-limit => joint.1.pos-lim-sw-in

But when trying to apply this example the error appears:

hm2_7i96s.0.7i77.0.0.analogout0-scalemax not found

The board The 7i77 electronics have all the necessary voltages, all the yellow LEDs are on and the green one too.

I have already managed to control the output and input through the classicladder, but unfortunately I am not having success in controlling the Z axis.

The HAL configuration is

loadrt hm2_eth board_ip="10.10.10.10" config="num_encoders=8 num_pwmgens=1 num_stepgens=5 sserial_port_0=3000"

Note: the number 3 in sserial_port_0 was necessary to recognize the 7i84d

How do I solve the error problem: hm2_7i96s.0.7i77.0.0.analogout0-scalemax not found?

I appreciate any suggestions or basic examples for configuring the 7i77

vre wrote:

Where can i buy both cards and thcad2 from europe in good prices ?

www.eusurplus.com
www.welectron.com/navi.php?k=324

Hello.
7i48 has 6 channels by muxing has this any limitation compared to 7i37 ?
Where can i buy both cards and thcad2 from europe in good prices ?

I am attempting to connect a THCAD 10 to a Everlast supercut 50. It does not have any CNC connections. It is a HF machine and I was told I needed to connect to the DC plasma supply before the HF coil. I am looking for pictures or a wiring diagram for this machine. I can not find anything. 

Thank you for the info

sharp_reaper wrote:

When I turn on QTPlasmaC the value of Arc Voltage is 145.
The encoder velocity pin seems to be working fine on halshow.
 

Sounds like you have not correctly calibrated qtplasmac for your THCAD settings
The THCAD 0 volt frequency should be what you observe on the encoder velocity pin give or take some bouncing around.
This offset needs to be entered in qtplasmac.

If you read the QTplasmac docs, there is a link to a calculator to determine your settings.

One 2.4M resistor in series to the negative lead will give you a 250V full scale range
which should be OK

Would the resistor I have listed work for the THCAD to read the voltage?

So I was able to double check for short/faulty cables on P1. I've disconnect the encoder connector from 7i96s and no contact to GND.
Made the change of the location of the THCAD board to the outside of the plasma source in a plastic box.
Connected the shield only on the 7i96s side in the pin TB2.9 with the GND cable.
When I turn on QTPlasmaC the value of Arc Voltage is 145.
The encoder velocity pin seems to be working fine on halshow.

What you recommend to do?

Thanks in advance, really don't understand what's happening.

Thank you for your advice!

The THCAD is mounted inside of the plasma source near the control board.

I'm making the recommended change for a plastic box outside of the plasma source.

This is the first Thermal Dynamics equipment that I work.
I've worked with several Hyperthem plasma cutting systems. All of those got an THCAD inside working well.

The THCAD boards seems to be fine. I have to check the encoder inputs from 7i96s but appears to be usable.

I am making that change to the future plasma systems to guarantee the best care for the boards.

When I have the chance I will make the changes and update you.
Thanks

rodw wrote:

But as PCW says, seeing 0 volt and 45 volts indicates it is working.
 

As i understood, he had 0V before firing the torch, and after the first firing it drops to -45, that absolutely points to THCAD working prior to firing and fails miserably after the firing as be it THACD output or 7i96S inputs are gone from the huge amount of EMI the actual torch firing causes and THCAD being enclosed inside a metal case where the source of all that EMI is.
-
The THCAD should be wired at the rectifier, not at the plasma output.
And yes, i have a THACD10 wired directly at the output lugs on an inverter plasma, but i would never advise that.
-
Just to be clear, yes you can mount the THCAD inside the plasma source, but absolutely should be avoided by inexperienced members of the human race.
The plasma source has a plethora of warnings plastered all over it, and the manuals spend several pages describing just how dangerous those things are.

The 200XT may be a HF start device. hyperthem machines that size are. This might mean you need to connect the thcad upstream of the HF generator. If not, It's likely to have damaged the THCAD or the 7l96 encoder. Tommy is the expert in this area.

But as PCW says, seeing 0 volt and 45 volts indicates it is working.

Rather than look at the reported voltage, check the encoder velocity pin in halshow. When not cutting, it should hover at or near the 0 volt frequency. Also it should be bouncing around. If it isn't and just a fixed value either there is an error on your encoder config in HAL or there is an issue on the high voltage side.

Using the plasma bit file, you have 3 encoders so damaging one encoder might have an easy  work around.