RTD input card (1769-IR6)

[adamp]

Hello, im using a mircologix 1500 plc with a 1769-IR6 rtd input card. I am having trouble getting the readings from the rtds to displays as values in rslogix 500. Any feedback or information on this would be greatly appricated. Thanks!

 

[sthompson]

Welcome to the Forum!

What Scaling Type have you selected in the IR6 Card?

What form do you want the Values to display in?

Stu.....

 

[adamp]

Thanks for the reply.
Ive selected raw/proportional for the data format and upscale for an open circuit condition. Which is the value currently being displayed on the screen. Im not sure which scaling type i have selected. My main problem is getting any value from the rtd to display in a MOV having source as I:3.0 and dest as N7:1. Once i can get a value to display within this function i think ill be able to figure out the scaling.

 

[Mickey]

Post your .rss file, zip it first.

Are you getting any reading at all, if so what?

What type of RTD (PT100 or ???)? 2 wire ,3 wire, 4 wire?

 

[adamp]

Yes, im getting the upscale reading of 32767 displayed. Im using a 100 ohm PT 385 and its a 3 wire rtd

 

[sthompson]

Yes, im getting the upscale reading of 32767 displayed. Im using a 100 ohm PT 385 and its a 3 wire rtd

If you are reading Upscale, that would seem to indicate a wiring problem with your RTD.

Stu....

 

[Ron Beaufort]

My main problem is getting any value from the rtd to display in a MOV having source as I:3.0 and dest as N7:1.

is the Source of the MOV command changing - but the Destination doesn't? ...

if the MOV command is in a "new" subroutine (ladder) file, make sure that you've included a JSR (Jump to Subroutine) instruction on an unconditional rung back in Ladder File #2 ...

 

[adamp]

When I check across the exc and sense inputs on the card im reading 108 ohms which is about the right reading at room temp. I think my problem is I:3.15 will not stay at 1 which enables the channel.

 

[adamp]

No, the source and destination value are the same. Which is the upscale value of 32767. Also there is a JSR in place. I have even tried bringing in the value on lad 2 with no luck

 

[Mickey]

When I check across the exc and sense inputs on the card im reading 108 ohms

Exc and sence?? See pdf. Check your wiring.


As sthompson pointed out.

 

[adamp]

Thats exactly how i have them wired. Also get a reading of 108 ohms across sense and rtn

 

[sthompson]

When I check across the exc and sense inputs on the card im reading 108 ohms which is about the right reading at room temp. I think my problem is I:3.15 will not stay at 1 which enables the channel.

I:3.CH#/15 is part of the Measured Value, not the Enable Bit. The IR6 Card Setup is done in the I/O Configuration for the ML1500.

Can you Post your PLC Program? (Zip it first)

Stu....

 

[sthompson]

Thats exactly how i have them wired. Also get a reading of 108 ohms across sense and rtn

That would indicate between 20 and 21 Degrees Celsius, which is probably about right.

Stu....

 

[adamp]

Not sure how to create a zip file.

 

[adamp]

That may be my problem. Im also not sure how to set up the i\o configuration.