plc 5 analog card

i am currently trying to control a ife2 b analog output card. i get intermitant changes happening. sometimes i can change the output and most times i can not.
i used the auto config in rslogix. even went as far as deleting most of the program, leaving just the btw and btr, and still the same problem.

can anyone help? please.

I dont understand this...an analog output card (from any plc) is dependent on the program...ie the analog output is dependent on what the program tells it what to use.

Maybe you should offer more details...from ife2 I assume an AB system.

State the system etc and maybe post the code that shows where the output gets the data it uses then state the specific problem why/what you cant change.

The basics:

IFE is an INPUT card
The output card is OFE

IFE/OFE--that may be the crux of the problem!!! Stranger things have happened to me. Or should I say, I have caused stranger things to happen.

Gerry you got me on a DUH there, I knew that too. Brain in neutral again.

1771-RTFM

Okay, let's start from the beginning with a little bit about your architecture.

I presume you have a PLC-5, as well as a 1771-OFE2 analog output card. There are three kinds of general-purpose analog output cards for 1771 I/O, the OFE1 (0-10V), OFE2 (4-20mA) and OFE3 (0-50mA).

Any analog card in the PLC-5 communicates with the controller via special commands in ladder logic called Block Transfers. (BTR and BTW for Read and Write).

I'll ask several questions of you:

1. What model of PLC-5 are you using ?
2. Is the analog module in question in the chassis with the PLC-5, or in a remote I/O chassis on RIO or ControlNet ?
3. Are there other analog modules that work, and are they near this module in the chassis ?
4. Is this a new program and installation, or was this working in the past and stopped working ?

You'll find that your block transfers are controlled by "BT" data structures (in modern PLC-5's with Remote I/O. PLC-5C ControlNet and old PLC-5/25 and 5/15 are different). When you set up a BTR or BTW, you enter the Length of the block transfer in Words, and the instruction echoes back the length if the BT was successful. If the BT fails, the BTR or BTW instruction returns a negative number in the Delivered Length field (.DLEN in BT parlance), the value of which designates the error code.

The method I use to trap a periodic block transfer failure is to count both .DN and .ER bits in the block transfer control file.

Just Guessing

Yendorcs mentions using autoconfig in RSLogix - by this I'm guessing he means the auto generation of the ladder rungs and data table for the BTX. If he selected IFE when he should have selected OFE.....

That was the gist of my earlier response.

I missed your point entirely as well, Gerry. zzzzz

Pontificatin' to the crowd, I guess.

Hey "yendorcs", go back, do like Gerry says and check the module part number in your Autoconfig, then report back.

thats guys. the problem was the scaling was not established and the meters we were using had problems.

thanks for your responses.