Twido Coil

[Greg 0]

Good morning guys. iv got a mission to do next programming and not really succeed in this maybe some one could help me, in S7-200 PLC from SIEMENS i know when i put a Reset coil it sets the value of the same Output or bit to 0 iv tried the same in Twido and i noticed it activates the reset coil when the same bit set to 1. my requirement is to open/close on/off valves, 1 of the valves should be open every time, and when i choose another valve to be opened the previous should be closed. i try to do that with Reset coil to the bits that have been activated in the HMI, but as i see the reset coil activated when the same bit are activated and not when the logic expression are true, see below the example. thanks in advance hope some one could help and explain how does it work in this PLC. Best Regards, Greg.

[aggattapauer 2]

I really don't understand your topic. I didn't see any example... Are you programming in Ladder or Instruction List?? As far as I understand the two valves are interlocked so that if one is opened the other is closed. Right? In such a case you have just to command (by any logic, or direct command from HMI. ect.) only one valve. After that you have just to copy the negated output of this valve to the second valve. LD %M0 (command to first valve) ST %Q0 (Output to open first valve) LDN %Q0 (when first valve is not opened) ST %Q1 (the other valve will be opened)

[Greg 0]

Hi aggattapauer, forgot to attach the file... im programming in Ladder, in case iv got more than 2 valve lets say 5. im choosing first valve to be open for my process, after it done what it should do, i want to choose another one lets say 4th and in that same action i want the first valve to change its position to close position. i had an idea with "Reset coils" as shown in the attached file, but as i saw the logic expression to start the coil didnt influence the coil(%M0), but it's bit(%M0) it self(for example that bit get's it logic from HMI). lets forget about the valves, how does "Reset coil" works in twido? Best Regards, Greg.

[aggattapauer 2]

How many valves you have to manage? How to manage them? Which conditions? In your attached file if %M1 goes 1 then %M11 goes 1 then %M0 is reset to 0 So as I see everything is correct and the function R works fine. Pay attention!! Don't make difference between coil and bit. %M0 is a read/write internal digital variable (on/off, 1/0, true/false). In your case as you say you have an HMI writing that variable, so it's possible (but I don't think so) that the PLC try to set the variable 0 and HMI to set it to 1, and in this "battle" only the last command will win!! On the contrary, if it doesn't work, I think it's because there's something else in the PLC logic. Instead of work with set and reset functions, try to consider to work with integer and function related to it (AND, OR, XOR, or simply some math logics)