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Willard

MT Developer 2

5 posts in this topic

Posted (edited)

Good day everyone,

I am working on a problem on a Mitsubishi Q series PLC and motion system. The system consist of a Q12H PLC CPU and 2 x Q173CPUN Motion CPUs. The first motion controller controls 23 x MR-2JS-_B Servodrive and thesecont motion controller CPU controls 6 x MR-2JS-_B Servodrives. They are all using SSCNET1 system.The machine have been working fine all along until the machine stoped for 3 months because we were waiting for one spare part that was coming from oversees during covid lockdowns.

When we restarted the machine, the servodrives could not home. When we were busy checking for the problem and before finding the problem, the machine just started homing. This keeps on happening over and over. Everytime you stop the machine overnight, it just stop working then when you are busy troubleshooting, it just come to like.

In the time when it is not responding, we figured out that when we jog the servodrive controlled by second Motion controller CPU for the HMI, the drives jog fine but the servodrives controlled by first motion controller CPU does not respond. I have tried jogging the servodrives indipendently using Setup161E and they move . I even changed the motion CPU but to no success. When you monitor using MT Developer 2, the are no errors.

Is there anyone who might have an idea on what might be the probable cause

 

 

Screenshot (122) - Copy.png

Screenshot (123) - Copy.png

Edited by Willard
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I have no experience with this hardware or this system, but 30+ years of industrial automation experience tells me check the usual suspects first.

Have you monitored your power supply and bus rail voltages.  Almost sounds like something is slow to charge up after being down overnight.

Just my first thoughts.

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Sounds like some buried lithium batteries wore out during the extended downtime.

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On 6/11/2021 at 3:12 PM, BobLfoot said:

I have no experience with this hardware or this system, but 30+ years of industrial automation experience tells me check the usual suspects first.

Have you monitored your power supply and bus rail voltages.  Almost sounds like something is slow to charge up after being down overnight.

Just my first thoughts.

Thanks for the reply, i have monitored the Servodrive system and the power supply is fine but the bus voltage at time drop close to 200Vdc but it doesnt reach 200Vdc. According to the manual, when the bus voltage goes below 200Vac, the drive automatically gives an alarm. I ll try changing these drives dropping bus voltages and see how the system goes

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On 6/12/2021 at 6:55 PM, pturmel said:

Sounds like some buried lithium batteries wore out during the extended downtime.

I have have opened the Motion CPU and the battery voltage is rated 3V and the measured voltage was 3.2V, i have changed the lithium battery for doubts elimination but still having the problem

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