Pt100 inputs

[craigb]

Hi, firstly I'm using a 821, pt12 b with CPU and mfd 80 with CPU.
Mfd is net 1, pt is net 2 and 821 is net 3.

My program is installed on the mfd CPU.

I'm using 2 x pt 100's

the help file says the plc automatically assigns IA1 to the input one on the pt 12 and IA2 to input 2 on the pt 12.

My mfd is set to display the value of IA1 as a word and IA2 as a word.
My program has 2 comparator blocks using IA1 and 2 against a constant value.

When I connect my pt100 as per drawings with link I don't get any values.
Is there more options to configure this. Do I set the inputs as IA or MD ?

[Maikky]

Dear craigb.

As far as I understood you only have one program in Net-Id1 and you like to use
the Net-Id's 2 and 3 as remote - I/O stations without program.

This works fine as long as your inputs are of digital type only. For analogue inputs
like your PT100's this method is not usable.

You need a small program at Net-ID2 to send the values by PT-function and at Net-ID1
you need a sequence to receive the values with GT-function. Therefore you also have to
change the type of sending/receiving digital informations to RN- and SN-function.

At the moment you are displaying the analogue values of the local inputs (IA1 of Net-Id1),
which is 0.

Regards
Maikky

[craigb]

Thankyou, that makes sense

later on I will have a go at the program on net 2 (pt 12 b)

I assumed automatically that net Id 1 (mfd Titan display) woudd automatically use the IA's of another station as net 1 doesn't have any inputs.

Is there any examples of programs that use this function to send analogue inputs over net? I assume it's just a case of sending a word fron net 2 to net 1?

[Maikky]

Dear craigb.

Attached please find a similar example.

Regards
Maikky

[craigb]

Thank you for that. I managed to write the program before I was able to look at the example, It wasnt as hard as I expected.

I did have a problem initially of ID2 sending one value to ID1. Where you used Marker 1, I used a flashing timer with 20ms delays.

The hardest part was trying to work out the scaling. Is there a formular for this ?

Will I also have to put ID 17 - 23 in ID 2 (Pt12 B)

While Im on this subject, every time I open my program I get a message popping up that says your program contains one or several unsupported expansion devices, they will be removed from the configuration.
I press ok, but nothing changes and I get this every time.
Doesnt seem to cause a problem but indicates something is wrong.

[Maikky]

Dear craigb.

Maybe it's useful to upload your program "as is" so others can have a look whether there
is something wrong.

Regards
Maikky

[craigb]

This is the program on my laptop I have now. My revised version that I done today with the Get and Put's is on my work laptop. This version is more or less identicle.

[craigb]

Just to add,

The 'R' inputs were only used for simulation purposes as at the time of writing I never had the PLC with me.

I used 'R' as there was no way to simulate the NET ID3 inputs.

[Maikky]

Dear craigb.

To delete the warning message of unsupported devices you have to re-configure your modules.

- select the first module at project view
- right click, a window pops up, select  exchange ?? (see attachment 1, I am using the German
        version and do not know the English menu item)
- the module changes colour (see attachment 2)
- pick the same module and place it
- repeat for the remaining modules

Now the message does not appear any more.

Regards
Maikky

[Maikky]

Dear craigb.

You are able to simulate the received bits from Net-Id3.

During simulation select the display view  -  RN Receive Bit  -  NET-ID3 and mark the proper
bit (for example RN1 in attached screen shot).

Regards
Maikky

[craigb]

Thankyou for your help once again, It has been much appreciated...

Another problem 

Ive atached the latest version of the program, It will not let me assign any inputs or outputs to NET 2. Net 2 being the Tp12 b module withi has digital inputs.

If you press simulate you will see the error pop up.

[Maikky]

Dear craigb.

The problem is related to my earlier answer. Net-Id2 has to contain a program, because
you are using analogue value. It is not a remote-I/O module.

Therefore you also have to change the type of sending/receiving digital informations to
RN- and SN-function.

Attached please find the modified program.

Regards
Maikky