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# Sequence With 3 Digit

## 10 posts in this topic

Hi people, I have done a program that compares the 2 Digit sequence from a Scanner reading to the last scanner reading. I move this 2 digit from the read result to a new Word and then i do a compare with the last read, and to a total sequence number, as in the first 2 pictures. Well after some help from some forum users it's done !!! But i have a last problem... i need to controll 3 number sequence... and then i can't compare with CMP since it occupyes more then a word :|, im very noob in the PLC world... is there a way to compare the values in the (D530&D531) and (D540&D541). Or treat them as only a value ? Is there any way to do this ? there is an example of the actual reading in the last picture. Sorry for my english... i can try to explain more clearly if there is any dought. Thanks.

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How about CMPL - compare long.

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Well i can't seem to get the right compare with CMPL... For example this situation: The value in D542 has to be = to the value in (D572 + 1) in the picture below. The +1 is in the D552 Position (can't see in text mode) That's when i have the 2 digit.. i can +B(404) to the D572 an then compare the D542 with D572. With 3 Digits i don't know how to do that... or more simple... how can i do the +B(404) with the 3 digits occupying the 2 words ? Thanks. Edited by OdinPT

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Hi OdinPT, Just as a side note: when you want to use a fixed number in an instruction, you don't necessarily have to specify a word (DM) that holds this value. Instead of entering the D542, you can also enter the value you want to be added, in this case #1. # sign indicates use of a BCD value, & indicates use of an decimal (integer) value. Now to your question; if you want to add a double word, use the +BL instruction. Be careful not to overlap words when using instructions with double words! For instance: So this instruction will do the following: (D542,D543) + 1 = (D572,D573) Instructions that use double words always need the operand words to be consecutive. I suggest you download the CS-CJ Instructions Reference Manual, it is a very good reference for using instructions. Hope this helps!

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Hi, I was seeing this instruction :), ok i will study a little bit more, as soon as i complete this program i will put it here in the forum and make a full description of what it does. Thanks for all the help.

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Yet ! As you can see in the Picture im doing the sum to the D540 +1, the D571 should be .899 and it is .998, is adding the 1 in the first left digit and it should be in the first right. I understand that it starts from the left to right, but is there any way to overcome this ? to do the normal sum ? Other thing... even if i can do that... when i sum +1 to the value .899 it should appear .900 and it appears .89@, i think that is because is BCD and not normal real values... Other problem Thanks. Edited by OdinPT

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There appears to be something wrong with your monitoring window - there are only 2 digits showng. If set up for BCD each word will show 4 digits - if binary there will be 5 digits I think in each channel. What word type have you set up to monotor in the window?

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The monitor is set up to Text because if i put it in Hexa is more dificult for me to understand what im reading... but yet..for example 98 TEXT is = to 3938 Hexa so its the same i have to work with 2 words. Thanks.

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Hex is really pretty easy. Use the Windows calculator to convert. Have you tried BCD? ASCII (text) may be giving you wrong readings.

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OdinPT, download this tool. It helps understanding and converting HEX values to binary and decimal. This tool will help you translate the ASCII values to the HEX equivalents. This explains ; you are monitoring in text and your ladder instructions are using HEX values! Adding #1 in a +B instruction does not mean the text value of the word you are monitoring will increase by 1! This is a fundamental thing you must understand.