PLC driven cutter machine

[Wefinish]

Well, this is been a pretty big day so far. After all this time, it's finally nice to see my driver head traveling back-and-forth under the power of the motor.
After spending half an hour playing with the VFD I am ready to start troubleshooting the other aspects.
Any knowledge out there regarding the communication link between the jazz drive and the D700 VFD?
I think it will work with Modbus.

 

[Lancie1]

What software does your Unitronics Jazz PLC use? I have Unitronics VisiLogic version 9.5, but I don't think it covers the Jazz Micro models.

 

[Wefinish]

The Jazz runs on U90Ladder

 

[keithkyll]

I'm not sure a low cost PLC platform should be your first choice. Would you consider a PC based platform? Mach 3 is under $200 and free to try. There is a wealth of information and blogs.
Parallel port is the I/O. Use a Breakout Board (BOB) to interface to hardware. Higher cost options for USB and Ethernet, etc. If you have interest, I'll elaborate further.

 

[Mill_Control]

Any knowledge out there regarding the communication link between the jazz drive and the D700 VFD?
I think it will work with Modbus.

How much communication do you need between the plc and vfd? On face the complication of modbus sounds like overkill for an application needing 2 outputs and maybe a couple inputs.

 

[Lancie1]

On face the complication of modbus sounds like overkill for an application needing 2 outputs and maybe a couple inputs.

Exactly, I was thinking the same thing. I would take care of the 2-second Ramp Up and Down by setting the VFD internal Accel time and De-accel times in the VFD parameters to 2 seconds each, then use a PLC timer AND the prox switch on each end-of-travel to stop and reverse the cutter-head direction. The 2-second Accel and De-accel times will only work if the VFD has enough power to accelerate and de-accelerate your cutter-head in 2 seconds. If not, it will trip out on overcurrent, probably on the De-accel ramp while using the motor for braking. For a 0.5 HP motor, 5 seconds might be more reasonable, depending on the weight of your cutter head assembly.

PLC inputs (You will not be able to easily send these via Modbus):
Prox 1 Left End
Prox 2 Right End
System Start Pushbutton
System Stop Pushbutton

PLC Outputs:
Run Signal to VFD (hard-wired but possible Modbus)
Stop Signal to VFD (hard-wired but possible Modbus))
Reverse Signal to VFD (hard-wired but possible Modbus)

Emergency Over-Travel for Stopping at each end (See Paul's Post #2):
Left Limit Switch hard-wired to VFD
Right Limit Switch hard-wired to VFD

The Emergency Over-travel circuits needs to be hard-wired regardless of whether you use Modbus to communicate the other 3 Output signals between PLC and VFD.

Emergency Stop Pushbutton and Emergency Stop Relay hard-wired to shut off power to the moving parts if something goes wrong. No Modbus should be used here for sure!

 

[Mill_Control]

Lancie,

IME the most likely problem with equal accel/decel time is overvolting the dc bus on decel unless the machine is mechanically "self braking". Ramping inertia up and down it'll be the decel that faults first with no, or internal, brake resistors.

And if the required decel time does overvolt the dc bus a DB resistor from automation freight and salvage is a cheap and easy fix IF the drive has a chopper that'll drive an external resistor.

 

[keithkyll]

Motor is only half-horse. Post #5 hints at self-braking.

 

[Wefinish]

The Jazz drive also supports GSM. Maybe I should be using that.

I have the JZ-PRG add-on which converts the Jazz port to MJ20. That is what I'm using to communicate between the PC and Jazz.

The D700 has an RJ45 port. Maybe it is a simple thing to convert from MJ20 to that.

Also, I anticipate the machine breaking fairly heavily but if I need more freaking time or distance I can accommodate that mechanically if I need to.

Finally found a website which does a good job detailing the D700. Excerpt below.

http://www.meau.com/eprise/main/sites/public/Products/Variable_Frequency_Drives/D700/default

The D700 series is the direct replacement for the S500 & S500E series and includes the following improvements:

Increased capacity up to 10HP in both 230V and 460V
Safety stop compliant
RoHS compliant
Includes brake chopper circuit as standard
Modbus RTU included as standard via the RJ45 port
Password function
General Purpose Flux Vector Control (same as E500)
Optimum excitation control for increased energy savings when motor is not under load
Frequency search function to catch a spinning load
Same mounting holes and dimensions as S500(E)
Standard 5 year warranty

 

[Lancie1]

IME the most likely problem with equal accel/decel time is overvolting the dc bus on decel

Yes, I should have just said it will fault on a 2-second deaccelerate, and left it at that.

 

[Lancie1]

The D700 has an RJ45 port. Maybe it is a simple thing to convert from MJ20 to that.​

Why not use the built-in digital setting dial to configure the D700 drive? Unless you have 5 or 10 D700s to configure, that seems the easiest, fastest, cheapest method.​

Simple to Set Up: The integrated digital setting dial with display makes configuration fast and easy.​

Also there are a couple of keypads available (FR-PU07, FR-PA07) that can be used for configuration.

 

[dploof23]

D700 model FR-D720S-025-NA is 230 1-phase in, 230 3-phase out.

I am currently using several of the D700 series drives. Mine in particular take 1 phase 120 and output 3 phase 230. Nice units, never had a problem with them. Setting up the parameters Lancie1 is talking about is a breeze.

 

[Wefinish]

I've been experimenting with the parameters available on the drive. I can definitely program the run speed and ramp up/ramp down characteristics I'm looking for.
Now I'm beginning to wonder how much I can do without getting a PLC into the mix.
I don't need the PLC for the E-stop or limit switches.
I cannot see getting the motor stopped and reversed without it though.

 

[Lancie1]

I cannot see getting the motor stopped and reversed without it though.

It is possible to use your proximity switches, a Start pushbutton, a Start Pushbutton, and a couple of relays to create a Forward-Reverse control circuit that will signal the VFD when to Run Forward and when to Stop and Run Reverse. But for about the price of 2 or 3 electro-mechanical relays, you can probably buy a smart programmable relay that will give you more functions (such as timers and counters) and allow easier software changes and adjustments (instead of having it all hard-wired).

You could probably find one of the Eaton EZ Intelligent Relays (also sold as Moeller and Allen Bradley Pico Controllers) that fit your requirements (and your budget).

http://www.eaton.com/Eaton/Products...lays/EASY500700800IntelligentRelays/index.htm

 

[Lancie1]

This Eaton EZ program set up for a EZ-512-DC-RC intelligent relay with 8 digital Inputs and 4 digital relay outputs should be a good start on the logic for your cutting machine. The 4 timers in the program will need to be adjusted so that your VFD is given RUN FORWARD, then STOP (while the VFD de-accelerates to a stop), then a RUN REVERSE, then STOP again, then repeat until the STOP button is pressed, or the E-Stop is pressed. The E-Stop should be hard-wired so that the VFD is stopped directly (bypassing the EZ relay).