ML 1400 Temp Control

I have a Micro Logix 1400 L32BXBA with a 1762-OF4, and a 1762-IT4, wondering if someone has a simple project using PID, measuring with a K type t/c and controlling an output to a scr with 4-20ma

post your existing project ... even if all it does is show us how the I/O is configured, that would help us help you ...

without some details to go on, about all that we can do is quote what's already stated in the book ... (you've already studied that - right?) ...

and by the way - is this a "real world" project - or a student exercise for a class you're taking? ... we'll help either way - but we can give better help if we know where you're heading with this ...

and what are you trying to heat? ...

HI
I HAVE MICROLOGIX 1400 AND THERMOCOUPLE CARD 1762-1T4 I AM USING THERMOCOUPLE FOR TEMP HEATERS BUT I AM GETTING -20636 VALUE AND I DID'NT GET ANY mv on multimeter please suggest what to do how i am get an exact value.

hi currently i am working on packing machine.
prevoiusly cutomer using temperature controller in machine
now he used to 1762-IT4 card with micrologix 1400 plc.
i have two wire K- type thermocouple which i used to take directly on IT-4 card.
but i am unable to get any counts in Logic please tell us wht i have to do further

Please post your program, please zip it.

Thermocouple it4 CARD zip file

widelto said:

please post your program, please zip it.

Click to expand...

here i have attached a zip file

You need to call your subroutine (ladder 21)

Use a "JSR" (jump to subroutine) instruction in ladder 2 to call ladder 21

Check your polarity on your thermocouple wiring if you don't get a proper reading.

i use jsr and change polarity also but dint get any result.

MUKUL said:

i use jsr and change polarity also but dint get any result.

Click to expand...

Post the new program. Take a snap shot(save the program) with the PLC in the run mode and a connected thermocouple.

Thermocouple temp issue

Hii here i have attached screen shots please check and revert

Sorry MUKUL, that's way to small to read.

Please post the whole program its .RSS file . Zip it first if you can. Please tell us what you are trying to do with the "SCP" instructions.

From what I can see is that this is a very different program then what you posted before.

The card configured for "Engineering Units" will give you a value of -4540 to +24980 for a type "K" thermocouple. Note the implied decimal point.
As a type "K" thermocouple's range is -454 to +2498 Deg F.

A card configured for "Engineering Units X 10" will give you the temperature reading directly -454 to +2498.

hii thanks for ur reply

i have attached current logic of IT4 card but i am not getting stable values i at room temp i will get 50 degree and at 150 degree temp i ll get 149 and if i move to 200 degree then i ll get 191 degree temp

i am using engineering unit and -2700 to 13700 limit

please help me

With your card configured for "Engineering Units" the raw value in words I:6.0 thru I:6.3 will be the actual temperature with an implied decimal point of one place.

A type "K" thermocouple has a range of -454 to +2498 deg F or -270 to +1370 deg C

You have channels 0 and 1 configured for Deg F
Channels 2 and 3 configured for DEG C
.
So ..
I:6.0 is 919 which is 91.9 deg F
I:6.1 is 943 which is 94.3 deg F
I:6.2 is 326 which is 32.6 deg C
I:6.3 is 331 which is 33.1 deg C

All you need to do is divide the raw value by 10 to get the actual temperature.

I have no idea what you are trying to do with the "SCP" instructions. The values used within them make no sense at all.

If the temperatures do not look correct then make sure you have the CJC sensor connected ( Cold Junction sensor)

See PDF for more info on the type "K" temperature range and what configuring the card for "Engineering Units means.

Please take note of my edited post above. Some of the temperature ranges were changed.

thanks for your information...

but i am just taking my input min and max value for degree celcius which was given in ur attached table -270 to 1370 i am just convet my scaled value into Celcius