Wile E Coyote

Could someone tell me which is the best communication method to use in GX-Developer when using a QJ71E71-100 ethernet module connected directly to a pc. MC Protocol, Fixed Buffer Comminication (with procedure exsist control method), Fixed Buffer Communication (with no procedure control method), or Communication using the Random Access Buffer? Thanks in advance

I am trying to do as you suggested by using several SPD's and add them together to give me a reasonably accurate rev/min. I had the one line with a -----(sm400)--------------[spd x36 k6000 d75]-----. This was the giving me a reading of "12" at first start up speed. After looking at your advice I then started to introduce 5 more "spd" lines the same as the first but with "d76,d77,d78,d79 and d80". These I was going to then add together. Once I had written in all these lines and wrote them to the PLC, a Q02, all of them stayed at"0". After deleting the added 5 lines, the first one still remained "0" no matter how the amount of pulses changed at x36 which is an input from a proxy. Hope this is enough.

Why does the SPD instruction work at times and then not? It will count normally for a while and then give some wrong amount and then zero.

Had various Mitsubishi and independant "experts" sent in by Mitsubishi to sort out my problem of three servos lagging in a "draw control" system. The "experts" are from the UK and Germany and Zambia. Last week they spent four 9 hour days trying to get the Mitsi servos to do what I would have imagined to be quite a simple task. Nothing doing. They had to admit they could not get it working but assured me given enough time, they were sure they could eventually get the kit to perform. I was not able to give them "enough time" to get it to work and they have agreed to take all the servos and amplifiers and other equipment back for credit. I'm really put out with Mitsubishi. I don't think I will be dealing with them in the near future.

I would say that the pulses are too fast for the PLC to see. How fast are you turning the encoder? I have had a similar problem with a Q-series PLC.

I am using the SPD function at the moment. The problem is you have to multiply it by something to get to minutes. That makes it inaccurate by whatever you multiply it if it changes by 1 on the SPD calc. Originally from Durban myself. Thanks for the reply.

Has anyone got a neat little programme that works as a rev counter or product per minute accurately? I need to display a "Envelopes per Minute" on an HMI but I need it to be accurate. I have proxies where a pulse per revolution can be used. I have an Omron Cam Positioner module which gives 60 pulses per revolution. I have tried timers and counters and the "SPD" utility, not accurate enough. Can anyone assist? Thanks in advance. What I need to add is that I need to count up to 1500/minute. Thanks again

I have put a firecracker up Mitsubishi's jib. All of a sudden I have all sorts of people from Mitsubishi swarming all over promising that all will be rectified by Monday evening or they will admit their equipment they recommended is not up to the job. I will post the outcome.

I do not have all the right gear to connect up the "OscilloScope" to the motion controller to get the actual lines of how they are following etc. Thanks again for your reply

Correct, I am using the mechanical designer. I am using a virtual encoder attached to the main shaft with 2 continuous gears and one spindle gear driving 3 output rollers. The first gear is set to a ratio of 14/1 and the second gear is set to 12/1 and the third gear is set to 8/1. The three axes are connected to three rollers for draw control. The acceleration and decceleration I mentioned is that of the main drive which drives the main shaft to which the MR-HENC is connected. I am using "Auto Tuning 1" and have the SV Response setting as high as I can before the Amplifiers come up with an error. I can monitor the command pulses and droop pulses. So far the droop pulses are about 13000 or there abouts on speed change. My problem is I need to know what parameter settings I can adjust which have an affect on the drives in "Virtual Mode" Many thanks for your reply.

1. The encoder is a MR-HENC which is part of the package which comes with the Q172CPUN and encoder module Q172EX. The encoder plugs directly into the Q172EX. The resolution is 16384 PLS/Rev. 2. I am using "speed control" in the "Virtual Mode" of MT Developer programme SW6RN-GSV22P. This is what Mitsubishi recommended. If you look on the Mitsubishi web sight you will see how impressive the mock up of all this looks. There is an example of "Draw Control" which is exactly what I am trying to achieve. 3. The problem with all the parameters and PID settings is my problem. The manuals and help files are as clear as mud. Running in this mode and following the encoder I am not sure which parameters and settings are actually effective. 4. The accel and deccel is 8 seconds and 5 seconds, really nothing fantastic. 5. The movement on the paper of the envelope is about 7mm. If you can visualise a line which is the score for the fold, on acceleration the paper lags by about 7mm and then after 25 envelopes it has returned to its original position. In other words one can see the fold and the score move. This is at about 300 envelopes/minute. We normally run at 1000/minute. Have'nt even seen how bad it is at higher speeds. Thanks for your reply. Pulling my hair out because of the lack of help from Mitsubishi.

I have installed 3 Mitsubishi 2Kw servos on an envelope press. The servos are HG-SF2024 and the Amps are MR-J2S-200B4. I am using them with a Q172 motion controller and the PLC is a Q02. The software is MT Developer for the motion control and I am running them in "Virtual Mode" as a "Draw Control". Everything works fine at a constant speed. The problem is when there is any acceleration or decceleration, all three servos do not follow the encoder exactly. There is a lag which moves the registration of the envelopes. It does correct after a short while. Has anyone had any experience with this sort of application. Mitsubishi people here are not able to help too much. Any help would be much appreciated.