Need help with Q68ADV configuration

[semwire]

We have a 8-year old machine which uses a Mitsubishi Q02H PLC with an analog-digital converter Q68ADV. The machine is seldom switched on. One day we found that the PLC battery was dead. After replacing the battery and downloading a copy of the PLC program with parameters, we found that the analog voltage inputs were not converted and displayed at the designated DMs. Question 1: How can we check whether the Q68ADV is converting the voltage inputs into data, and why are the data not seen in the DMs? Question 2: We are using GX Developer version 8, but without the utility package GX configurator-AD module. How can we configure the Q68ADV with just the GX Developer program? Any help is greatly appreciated.

[Crossbow]

The manual for the module has working examples of both with and without the configurator software. And you can use the buffer memory monitor in GX Developer to look at the registers inside the card. Are you certain the card was not set up with the configurator originally? If it was, then losing the battery and losing the PLC memory means you also lost the analog module parameters. If not, you should find code in your program (TO and FROM instructions) to initialize and operate the module.

[semwire]

Thank you for your reply. We are now more hopeful of getting it corrected. 1. We are aware of the examples in the manual and have been working on it. Your comments means we are on the right track. The problem is figuring out the correct references. 2. We have located the buffer memory and are able to see the data changing as the input voltage is varied. This shows that the hardware is ok. The issue is with the referencing. 3. In the PLC setup page, the setting for the analog module is still there. The machine was custom-made. We don't know how the card was set-up initially. But there was no programming lines in the PLC ladder for configuring the analog module. Will be working on it over the weekend. Perhaps we will put together some images and more detailed questions on what the correct references should be.

[kaare_t]

1 & 2. Which specific references are you looking for? You've found the BFM, you would need to use them in your program 3. If there's nothing in the program, the analog module has been set up using the utility pack - you should install the utility pack and see if you can read out the parameters from the project (the utility file is embedded in the program files in GX Developer)

[semwire]

Sorry, we are novices with the GX programmer software. We were looking for the references to be used with the FROM/TO command. Took a little while for us to identify the I/O number of the ADC and DAC modules, the address of the buffer memory, and the respective assigned DMs. We managed to reassign the DMs and now, the analog inputs were converted to digital data, and after calculation, the digital data could be output as an analog voltage. However, there was another issue with the Offset/Gain settings. We found no values were set in the buffer memory. Now, we have to measure and do a recalibration. We do not have access to the utility pack, short of buying one. What we don't understand is why certain parameters were not saved with the PLC program? Or is it because we did not have utility pack installed, hence we could not restore the parameters? In that case, would it be better to include the programming of the ADC modules in PLC ladder just in case the end-user do not have the utility pack installed? Anyway, thank you all for the valuable comments and suggestions.

[kaare_t]

You don't have to buy the utility pack, it is included when you install GX Developer... So in essence there's nothing wrong with using it, everyone that has purchased GX Developer or GX Works2 have these utility packs on the installation media. Good thing you've got it working!

[Crossbow]

Offset and gain are module specific. If you need to adjust them, then putting the program into another PLC you will need to adjust for the new analog module. That's why they are not stored in the PLC program. Modules are factory calibrated and typically don't need to be adjusted in the field.

[semwire]

Oops! Were we using a "pirated" copy? The software was already installed in a notebook. We do not have the installation CD. Thank you for your comment.

[semwire]

Your point is noted. Thank you.