rslogix timer problem

I am new to RSLogix and am trying to set up a simple TON timer. I have given it the following parameters:

Timer T4:1
Timer Base 1.0
Preset 3
Accum 0


As near as I can figure this should get me a 3 second Time On timer. But all I get is this error:

Invalid output instruction position.


It seems to be pointing me at the Accum field. Any ideas what this is trying to tell me?

Can you post a screen shot of your rung(s) of the logix file

TOn is an output Inst it should be at the end of the rung
If more then one output Inst all output be in parallel at the end of the rung

SLC-500 controllers only allow output instructions (including TON, TOF, and RTO timers) as the rightmost instruction.

If you want to run an output from the status bits of a timer, put it on a parallel output branch or on another rung.

Example of wrong way:



Correct way:

thank you,

putting the timer to the right on the rung has cleared up my error. Now, how do I use the output from this timer? I had originally put a coil off the output of the timer and then was using it's contacts in other spots but now I don't have that coil available. Do I use a contact addressed with the same name as the timer? If so, what is the syntax?

The timer has associated bits i.e. TN = timer done TT=timer timing ACC is accumulator value, go to Help then instruction set and click on TON, it is defined there.

If want to use timer done its T4:0/DN The ACC in a compare etc T4:0/ACC.

that works! thanks

I just wanted to make a correction in case anyone views this thread in the future - based on Ron's excellent track record here and the amount of knowledge he has shared, I'm sure he was just in a hurry and didn't double check his typing in his post, I've made similar mistakes myself...

Anyways, the accumulator is addressed as T4:0.ACC, using a . instead of a /. The . is for designating a word address while the / designates a bit address.

For an on delay timer, TON,
T4:0.ACC is the elapsed time when the timer is running.
T4:0.PRE is ther preset time to which the timer counts.
T4:0/EN is the bit that is on whenever the timer rung is true
T4:0/TT is the timing bit, its on whenever T4:0/EN is on and T4:0.ACC < T4:0.PRE
T4:0/DN is the done bbit, its on whenever T4:0/EN is on and T4:0.ACC >= T4:0.PRE. (This behaves differently for an off delay timer - refer to the instruction documenation under Help in Logix500)

All of these bits may be used in your program and you may write any positive integer value between 0 and 32767 to the .ACC and the .PRE words using a MOVe, COPy, or any Mathematical function.

I stand corrected BUT to offer why I did not mention/think about this is the fact that RSL500 5.0 and later will automatically change the / to a . when entered into a compare, math, etc. instruction.

a note from the "other" Ron ...

here's a handy way for beginners to check the syntax of an address ...



this trick is also helpful for technicians who use the software only infrequently - and sometimes forget the proper syntax ...

using the click-and-drag method helps eliminate typing errors ...