Ti530c Woes

Here at the plant we have an old TI 530c processor. It has all 120v descrete i/0 cards.The problem is I am attempting to utilize one of the unused outputs on the last card but all outputs are turned on all the time on that card. None of the outputs on this card are used at all in the program. When I program in a rung utilizing one of them the status shows the output as low but it is still turned on with all the others. The card is configured exactly as all the others. Whats up? Any Ideas guys?

TI's use a common input/output image area eg. X1 and Y1 are the same memory location. Maybe the memory location the output card has been configured for is the same as one of the input cards. From what I rember of the IO configuration in Ti soft it does not check for overlapping addresses.

Andy Butcher

What do you mean "turned on"? Are you measuring voltage at the screw terminal? Is it a triac output? Remember all triacs leak voltage with no load applied.

Hi

From what you say, the appearance of the logic when viewed in Tisoft shows the output as off? But all the outputs on the card are physically on?

Even if AndyButcher's suggestion of the duplicate assignment of input address and output addresses (Xnnn and Ynnn) was correct, the logic writing to an output should win every time. Even if the input Xnnn is one at the start of scan, by the time your logic has said that Ynnn should be off this is the value that gets written from the image register to the module at the end of scan.

How about wiring? I don't know the minimum load this module should be connected to, but maybe it's not physically capable of turning off its outputs because of v. low impedance or similar?

Finally I don't know whether the LEDs on these module are wired logic-side or field-side. What exactly are the symptoms you're seeing?

regards

Ken

First thanks for your replys. Andybutcher hit it right on the head, we figured this out last night. I was Checking the outputs with my multimeter and of coarse was showing full voltage. It turns out my "problem" was not a problem at all. Just that the leds being lit up when their respective elements didn't even exist stumped me. As Bart Simpson would say DOOOHHH!!!
Thanks again for your help