1794-IR8 module scale

JLU

Member
J
Join Date
Aug 2010
Location
Pennsauken, NJ
Posts
5
HI, I need a help!

Recently, I had wired a RTD Pt-100, a=0.000385, range at: -328 to 400'F temp. sensor to the I/O Flex RTD module: 1794-IR8. I used scaleis: -3280 to +15980 which is recommended by 1794-IR8 Module manual: Allen-Bradley Publication 1794-6.5.4 page 4-3. Somehow it seems not quit correct. I have recieve the scale output is -160'F while the true temp. should be around 87'F.

I don't know where I was wrong. Could anyone can help me with the above question to let me know how to scale it?

Thanks a lot.
JLU
 
JLU said:
HI, I need a help!

Recently, I had wired a RTD Pt-100, a=0.000385, range at: -328 to 400'F temp. sensor to the I/O Flex RTD module: 1794-IR8. I used scaleis: -3280 to +15980 which is recommended by 1794-IR8 Module manual: Allen-Bradley Publication 1794-6.5.4 page 4-3. Somehow it seems not quit correct. I have recieve the scale output is -160'F while the true temp. should be around 87'F.

I don't know where I was wrong. Could anyone can help me with the above question to let me know how to scale it?

Thanks a lot.
JLU
Click to expand...

What PLC and Communications Protocol are you using with the IR8? Did you write the proper Configuration Data to the IR8 before trying to use it?

Stu......
 
It is SLC-500, CPU 5/05, through a DeviceNet Module 1747-SDN. Therefore, the data read to SLC by copy message block M1 file.
 
JLU said:
It is SLC-500, CPU 5/05, through a DeviceNet Module 1747-SDN. Therefore, the data read to SLC by copy message block M1 file.
Click to expand...

I haven't used an IR8 on Devicenet, but I have designed and installed a number of Devicenet Networks. You should be able to set up the IR8 as I/O. Reading and writing to the M files interrupts the PLC Scan, and is best avoided if possible. There are Configuration Words you should write to on startup with the First Scan Bit or other method. This will set your Ranges etc. Have you set that up in your program per the Manual information?

Stu......
 
Thanks, Sthompsom.

What I did, is simple copy the M1 file to N file:

COPY File:
Souce: #M1:1.19
Dest: #N12:100
Length: 40

How should I do it? I might need to read the Manual again. Thanks.
 
JLU said:
Thanks, Sthompsom.

What I did, is simple copy the M1 file to N file:

COPY File:
Souce: #M1:1.19
Dest: #N12:100
Length: 40

How should I do it? I might need to read the Manual again. Thanks.
Click to expand...

Do you have RSNetworx for Devicenet so that you can set up your Devicenet I/O? You should be able to add it to your Devicenet Scan List.

Stu.....
 
I did completed the DeciveNet configuration by using the RSNetWorx. Therefore, I can read all the RTD Module 8 ch. data to the N file. I have just learned that my precidouer engineer didn't write any config word to identify the RTD sensors on M0 file. Is it a main problem that I can't get a correct reading? I will give it a try.

Thank you so much. Stu!

JLU
 
JLU said:
I did completed the DeciveNet configuration by using the RSNetWorx. Therefore, I can read all the RTD Module 8 ch. data to the N file. I have just learned that my precidouer engineer didn't write any config word to identify the RTD sensors on M0 file. Is it a main problem that I can't get a correct reading? I will give it a try.

Thank you so much. Stu!

JLU
Click to expand...

If the IR Module is properly configured, you should be able to read it as a regular I/O Word, and write to the Configuration Words as I/O as well. This is much more efficient than us the M0/M1 Words. As I previously mentioned, accessing the M0/M1 Words interrupts the PLC Scan. Can you post your PLC Program? (Zip it first)

Stu.....
 
Hi, Sthompson, I am going to leave here for a while and will be back soon. Again, Thank you so much for the strong support. JLU
 

Similar Topics

P
How use sofware rslogix 5000 v16.0 calibrate flex module 1794-IR8
Anybody can help me. I already read document in software rslogix 5000 and I think i can use software rslogix 5000 calibrate for flex module...
Replies
0
Views
1,728
phamquoctrung
P
D
1794-IR8 RTD Module scaling???
I have a 1794 IR8 module I just installed on a cooling tower. It a PT100 RTD and I am returning a reading of 998 decimal. I don't know if I need...
Replies
5
Views
6,666
Kim Gold
Kim Gold
J
1794-IR8 Configuration
Hello everyone. I have installed a remote Flex i/o enclosure with a AENTR ethernet adapter and an 1794-IR8 RTD card. I have landed 4 RtdÂ’s on...
Replies
0
Views
786
Jameswhi
J
K
1794-IR8 failing in service, getting hot
Control logix CPU connected to Flex IO via Controlnet The Flex io consists of 5 modules IB10XOB6/A IE8/B IE4XOE2/B IR8 IR8 The 2 IR8 modules...
Replies
2
Views
1,994
kellian
K
D
1794-IR8 Problem, Unstable readings
Hi there have recently installed some Flex IO to replace some Solartron IMPS and an old style Emerson Scanner. But I am having issues with some...
Replies
0
Views
1,399
David Coles
D
Back
Top Bottom