AJ65BTB1-16D cc link thermocouple setup problem

[Kings and Barnhams Automation 0]

I am currently working on a project that uses a Q02 CPU programmed Q mode using GX developer which uses a cclink master QJ61BT11N. On the cc link network i have input, output and thermocouple modules installed in remote electrical control panels powered from their own seperate supplies. I can read temperature values back from all my thermocouples ok but the problem is when any of the cc link thermocouples is powered off i can see the last measured values remain constant within the remote registers Rwr starting at d3000. When i have re-established the power to the relevant cc link thermocouple module its Rwr registers all get values of 0 written into them and the only way i can start reading values once again is to re-write the program to the PLC. I have looked through the AJ65BT-68TD manual and the programming examples seem really over complicated to me. I have tried to pick out the parts that i need and set the relevent RY remote flags that i need to get it working by using SM402 first scan contacts but i am aware that in the manual examples Rx flags are used for request and completion of data flags. Do i need to be using these instead ? Has anyone got any explaination of how to get these working correctly or any setup examples they would be prepared to share? I have also seen that these can be setup by using remote device station initial setting procedure registration within cc link network parameters. Is this a better way to go ? This is the first time i have used cc link and am finding it a bit of a struggle. Hope this all makes sense to someone!

[Veganic 8]

First thing to try is to put a 'restart' bit in parallel with SM402. Down power on the remote station. Power up. Activate the restart bit and see what happens. I had a similar problem on a Q series temp. input (not CC link). I could not get it to restart after a wire-break/ unplugging with similar symptoms. In this case it wasn't a problem to PDPU if it happened.

[Veganic 8]

Just had a look at the powerpoint example in preparation for an upcoming project and it looks like you need to monitor the "Initial data processing request flag".

[Kings and Barnhams Automation 0]

Thanks for the info Veganic, i had no joy with using a restart bit as when i am monitoring software i can see when a thermocouple card is powered down the RY flags and channels that i have enabled are still turned on. I can also go into buffer memory batch monitor and see that the bits that need to be on in the relevant buffer memory locations are still on. Like you say it seems to be that you have to use the initial data processing request flag RX78 to turn on the RY flags and in the manuals programming example they use RX79,RY78 and RY79 as well. I have just tried a few ways of using these to control the RY flags but am still not getting it right. Is it possible that you could post your example to have a look at?

[Veganic 8]

I never got it to work with the Q series temperature card. I have looked at the programming example and the only other thing that may be worth monitoring is the data link status to your remote module (not M100 = data link ok in the example program from SW80.whatever in the master station). Maybe a falling edge on M100 to set Y79 then X78 resets Y78...as per the sample? It may be worth trying to send the Y79 signal during normal operation to see what happens and maybe try to change some parameters to see if it sticks? Edited 11 Dec 2008 by Veganic

[Crossbow 296]

CC-Link can attach and detach modules without bringing down the network. So my only thought on the issue might be the SB bits for the CC-Link master show which modules are present and in the data link. I would expect a bit will turn off when the station goes away, and perhaps that can be monitored to make code that restarts the module. Of course without the manuals, I have no idea what those addresses would be.

[Kings and Barnhams Automation 0]

Thanks for the ideas, unfortunately i cant get to site to try out your suggestions until the new year but i will let you know how i get on when i do. In the mean time if you have any further thoughts please dont hesitate to share them.