CPM1A-20CDT

[OdinPT 0]

Hi, My name is Carlos and im new in the Automation World, i bought a CPM1A and started using CX-Programmer 5.0. Im yet starting to know how to work with the program but it seems something is not right when i try to use the DIFD and DIFU. I want to use DIFU on my 000.00 input so it can activate the Output 010.00 (for example) , for that i use a Normaly Open contact that activates the DIFU in the bit 200.00 then in other network i put the NO 200.00 activating the output, but it doesn't seem to work.. each time i activate the input the DIFD doesn't do anything. Can anyone give a little help please ? Thanks.

[Guest Guest]

Seems like you don't fully understand the DIFU and DIFD functions. If you made this: ---| 0.00 |-------| DIFU 200.00 | Then 200.00 will be turned on for a single CPU cycle. So if you use 200.00 as a NO contact somewhere else in the ladder to control an output coil, you won't notice the output coil turn on because by the next cycle 200.00 is off again. What exaclty do you want to accomplish ?

[PdL 44]

That would be me

[PdL 44]

Why not collect the 5 sensors to a "release machine" coil if they are all present (or not, depends on the input type. e.g. |----|sens1 safe|---|sens2 safe|---|sens3 safe|---|sens4 safe|---|sens5 safe|---( )release machine

[PdL 44]

Put the sensor inputs all on an output coil of an internal adress. Say ---|P_ON|----|inp1|---------(200.00)            |            |-|inp2|---------(200.01)            |            |-|inp3|---------(200.02)            |            |-|inp4|---------(200.03)            |            |-|inp5|---------(200.04) Make sure that nowhere else in your ladder bits IR200.05 to IR200.15 are used. Now the word value (binary combination) of adress IR200 equals the input state of the sensors, that means regardless if they are on or off. Use a MOV instruction to move the value of word 200 in a DM, for instance DM10. Condition to execute the MOV instruction is "machine on" state. Now if the machine is set off, you have "recorded" the last valid state of the sensors in DM10. (MOV instruction isn't executed anymore) The actual sensor state is still the word value of IR200. Now use the compare instruction CMP to compare the actual sensor state value in word IR200 to the last valid sensor states in DM10. If it equals, the sensor states are the same as before the machine stop. If it is less or greater than, the sensor states have changed. Alternatively you can use the less or greater than bits (these are system flags that you can use in combination with the CMP instruction, look for them in the symbol list) to tell you wether the sensor states have changed in between. You could set a bit "input changed" with these contacts for instance. Hope this helps you further. I'm sure that once you have an idea which instructions you have at hand, it will be much easier to turn your ideas into ladder. P.S. In CXP, in the right click menu of any instruction you'll find "instruction help" it gives you a good explanation of the instruction's function, and how to use. The instruction help list is also accessible through the normal help menu. Edited 1 Jun 2005 by PdL

[Grizzly Wolf 0]

Maybe this will help you. Ejemplos_Omron.zip