Andrei Blagaila

AJ65SBT2B-64RD3 PT100 Module

8 posts in this topic

Hi guys,

I'm playing around with a PT100 temperature reading module (AJ65SBT2B-64RD3 ) and I came across something strange. I took the example program written in the manual and copied it exactly. It works but now I figured that some of it is not needed maybe and some is not clear what it is used for. Can someone explain what exactly do these two values are in the settings? I'm using all 4CH of the module so maybe I need to change something or I can just delete it if it's useless in my application. (I read the temperature in a room and turn on or off a IR Lamp depending on that temperature).

Thanks,
Andrei

1.jpg

Share this post


Link to post
Share on other sites

The hex code specifies the averaging method used to reduce the effects of noise or other unwanted disturbances. Basically like a software low pass filter. These will be explained in the manual for this module and you will find the hex codes there too.

The D register will be copied to the buffer memory on the PT100 module for the averaging settings. They've only set up CH1 and 2. Probably CH3 and 4 will be in D1002, D1003 but you might need to change the FROM/TO functions too.

If your temperature signals are not stable or too sensitive to things like doors opening etc., you might consider using averaging. Although it does delay the feedback to the controller, it shouldn't be a big deal in a temperature control application.

If you just delete those two rungs, I'm pretty sure all channels will just be on sampling mode anyway (they will just be 16#0).

Share this post


Link to post
Share on other sites

So if I want the real time value then it's better just to delete the lines? I want as fast of a reading in the temperature change as possible. Real time values not averaged values.

Share this post


Link to post
Share on other sites

If you just delete the lines it will be in sampling mode. If you do that then I think you will need to set another hex value so than the number of samples is zero.

Or there should be a hex code you can set so that averaging is off completely. But you will still have the delay from the ADC time. Please look in the users manual for the hex codes.

Share this post


Link to post
Share on other sites

Now I realised I have another problem. In the manual for the module there is an example program. Problem is that the bit X1018 that is the bit for the initial setting does not turn true to abilitate the conversion flags. I don't understand what I did wrong. If I put a -|P|- SM400 in paralel will it cause problems? I just want it to set everything once the PLC is powered up.

Share this post


Link to post
Share on other sites

Yes, just writing H0 should disable averaging. Or H0101 would also do so I think.

Are you sure you have the correct X and Ys. Check your cclink remote device map:

image.jpeg.c634bcbef46b5065cce3299220329

Is the cclink definitely communicating and the RTD station not in error? If it is working properly and you follow the program example only change device addresses for your hardware config, it should work.

Yes you could just enable the X1018 network with a one shot but you would have to do it after the network communication was established, not SM402. I suppose you could just wait 1 min with a timer and trigger it on the rising edge of the timer to see if it's working. But the right thing to do would be to get a program like the example working. Post a screenshot of any parts if you'd like me to explain what it's doing.

Share this post


Link to post
Share on other sites

I found out the problem. I was reseting the CPU but the X1018 was not transitioning to true. It only does that on Power Up. When I cut the power and put it back on it worked.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now