Guest Chido Posted October 23, 2003 Report Posted October 23, 2003 Hi everybody: Please help me. I am modifiying a program on a A2SH using GX Developer. I was doing some testing forcing signals with the IO disconnected and now will connect it and I am not sure how to remove all the forces that I did. I was wondering if there is a way like in RSLogix to disable and remove all forces at the same time. Do the forces remain? or if for instance the input (X10) is ON the force OFF will be overwritten with the real value? Thanks a lot..
navillusi Posted October 23, 2003 Report Posted October 23, 2003 (edited) Forcing on Mitsubishi PLC's does not work in any way similar to that of RSLogix. If you force on an output coil (eg Y20 or M100) it will be on so long as there is no reference to it in the program code, if there is reference to it in the code, you will turn it on and then after the next scan, the plc will turn it off again. Inputs work slightly different, you can turn them off or on as many times as you like and the PLC will evaluate them in whatever condition you set. Trouble is, there's no way of knowing what inputs have been forced! For example, you have an emergency stop button that gives a 1 for healthy, you are testing and force that input to a 1 by mistake, someone presses the stop button and the plc will still think it's ok! The only way that I know of removing all of the forces is to switch the processor to reset. Edited October 23, 2003 by navillusi
navillusi Posted October 23, 2003 Report Posted October 23, 2003 The device test dialog (alt+1) will give you a history of what devices you have toggled. Close the project and re-open and the history will be cleared.
Guest Chido Posted October 25, 2003 Report Posted October 25, 2003 Thanks Navillusi: I will reset the PLC to get rid of all the forces because I forced quite a bit of inputs, that could be dangeorus :*-(
Guest Guest Posted October 26, 2003 Report Posted October 26, 2003 Please someone correct me if I am wrong - but I always thought that with mitsi, you cannot force inputs ON. (Not to stay forced on anyway) or for that matter outputs either (IN RUN MODE) You can with the simulator (thats what it is for) but if the logic is not true, you cant force an 'Y' or an 'X' on
Guest jlhmaint Posted October 26, 2003 Report Posted October 26, 2003 You can force inputs or outputs on mits, X or Y you can not force M coils that i know of. I have been very busy lately but i will check my book at work and let you know. I went to a class at mits for there PLC a couple months back and got some good info give me a day or 2 and i will post.
Guest jlhmaint Posted October 27, 2003 Report Posted October 27, 2003 Here is mits site and a manual for the gx developer ver6, if you go to the debugging section it talks some about forces. I will still check my info at work and post back. http://www.meau.com/Files/IB_NA_0800031-D.PDF
Guest Chido Posted October 28, 2003 Report Posted October 28, 2003 jlhmaint: The link doesn't work...
panic mode Posted October 31, 2003 Report Posted October 31, 2003 It is usually not hard to find the manuals on www.meau.com but sometimes their site is VERY slow... Here is link to FX manuals
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