AB Thermocouple Analog card

TMcDaniel

Member
Join Date
May 2020
Location
Florida
Posts
41
So I finely got everything ready to go with me analog thermocouple cards and no having an issue with actual temperature. Here is the problem at room temp. with no heaters on the temp display on my HMI reads 85f-87f degrees which is pretty accurate. However, when i turn my heaters on they reach about 150f on the HMI dispay. (By the way this is on a Extrusion Blow Molder from the 70's that i have converted to Micrologix.) At 150f the plastic in the barrell should barely be hot enough to flow much less burn, but it is burning to a crisp. My other blow molder (still equipped with switches and relays from the 70's) run about 250f until the plastic will run and about 400f until it will burn. My guess is i dont have the SCP set up correctly.

I will post the pic of my logic.

pastedImage 3.png
 
Try input min set to 0

Edit: also what type of input RTD/PT100? and whats the input card
 
Last edited:
AB 1762-it4 card and im not sure what exact type of thermocouple they are i do know that they are j-type and they are not rtd
 
The only thing that jumps out at me... and this is a WAG, I have never had my input min set to -32767, I would try changing that to 0 first
 
Are you using raw?


From manual:


If you select the raw/proportional data format for a channel, the data word will be a number between -32767 and +32767. For example, if a type J thermocouple is selected, the lowest temperature of -210°C
corresponds to -32767 counts. The highest temperature of 1200°C
corresponds to +32767. See Determining Effective Resolution and
Range on page 3-14.
 
You don't need a "SCP" instruction, depending on how you have configured the card.
You can get a direct temperature reading, how do you have the card configured?

Post the .rss file if you can (zip it first)

See pdf for data format options...
 
Are you using raw?


From manual:


If you select the raw/proportional data format for a channel, the data word will be a number between -32767 and +32767. For example, if a type J thermocouple is selected, the lowest temperature of -210°C
corresponds to -32767 counts. The highest temperature of 1200°C
corresponds to +32767. See Determining Effective Resolution and
Range on page 3-14.


You hit the nail on the head. As soon as i set the scale min to -210 and the max to 1200 it was giving me readings within 10 degree of the thermal gun.
I was assuming when i loaded the program and it was reading around 87 degree (which is how hot it is in our shop) that it was correct. Thank you for the help.
 
You hit the nail on the head. As soon as i set the scale min to -210 and the max to 1200 it was giving me readings within 10 degree of the thermal gun.
I was assuming when i loaded the program and it was reading around 87 degree (which is how hot it is in our shop) that it was correct. Thank you for the help.


Wow, the blue numbers are °C; I find it hard to believe that red temperature of your shop is also °C ;).
 
You hit the nail on the head. As soon as i set the scale min to -210 and the max to 1200 it was giving me readings within 10 degree of the thermal gun.
I was assuming when i loaded the program and it was reading around 87 degree (which is how hot it is in our shop) that it was correct. Thank you for the help.


According to the manual, you can also put in -346 to +2192 to get °F.
 

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