Thanks.
I had the wrong configuration of my output module. The program and the hardware layout did not match with the ladder logic program. I corrected it. The one question I have now is that I want turn on each output of the 1762-OV32T module separately from the RS logix program using the output states(0 or 1) of that particular output. Please let me know how I can change such bits from the ouput screen. I double click on that particular output and change from "0" to "1" but somehow the change is not retained and I do not not see any change.
I could run separate programs and have a different output "on" with the program and it works. This consumes too much time for just testing each LED lighting up . My objective is to change the ( on(1) or off(0)) from the output screens on these 32 ouputs.
Any help will be appreciated.
The PLC protects against outputs being turned on by toggling a bit. Generally when dealing with process equipment, turning on the output is a serious thing. Damage to equipment or injury of personnel can occur if care is not taken. The PLC does have a method in which to force inputs and outputs on and off. if you right click on the output in question, you will see an option called 'force.' The force function allows you to force the output on or off. Once you force the output on or off, you will have to enable the forces in the program. You should see a list box in the upper left menu area that will allow this. If there are a lot of forces to take care of like you have, you can bring up the force table and manipulate multiple forces easier from there. They will show up as . if there is no force and a 1 or 0 if there is a force installed. When done, you should disable your forces and remove them. Note the the force light on the front of the PLC will indicate forces installed (blinking) and forces active (solid).
I did as you mentioned and forced the bits. I saw the light on the PLC ouput change and also saw the force light on but did not see the LED turn on. The force installed was "green" and the force enabled was" yellow". Although, what I did was I wrote a program where I latched and unlatched an output of the 1762-OV 32T and followed a sequence with these outputs with 60 timers and saw each LED turn on and off sequentially(30 total) for 1 sec time. Is there a way to use just one or two timers and change the outputs in a counter format so that the code is about 1/30 of the number of lines I have now.
Second queston:
Can AB 1100 PLC step a motor forward as revolutions or will it only send a output signal as on and off and the servo(2040) must be preset for the move for each time output signal is turned on?
I am not sure what happend with your forces. If implemented properly, forcing and output or input will override all logic.
Yes you could have taken one timer to a counter and used EQU statements to energize the outputs when the counter accumulator was at the correct value. You could have used the sequencer instruction or bit shift instructions also. There are always many ways to do any action in the PLC.
The interface to your servo unit is largely dependent upon the functions and interfaces available on the servo. The micrologix has discrete and analog i/o as well as serveral communication options. Usually simple is better. with the repeatability of the movements that you need, setting up preset movements in the servo unit that will act when it sees certain inputs would be simple and effective.
Hello,
In what mode of operation are your servo's running for example; direct talk mode, AC, PWM? I have done similar things using a profibus, estun EMJ servo, Kinco PLC and HMI. I simply figured out how many pulses will move me a certain distance and set up routines with those pre-defined positions and got feed back from an encoder that fed into a PLC input which tracked rising edge. Than i just had conditional statements according to the encoder pulse count to power my leds.
rafaelmc http://www.lcdtouchscreen.org
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