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Deer

Melsec Analog I/O addressing

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Hi All, I am familiar with AB PLCs but never use with Mitsubhisi PLC (Melsec A1S series) What I want to know is about analog I/O card addressing. Let say, I want to MOV value that comes from analog input module CHANNEL 0 that located at slot 3 (AIS63ADA) to analog output(A1S62DA)CHANNEL 0 at slot4 In AB PLC (SLC series) this can be done use MOV I3:0 to O4:0.Simple.. How about with MELSEC PLC, anybody can help? Thanks in advanced Deer

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Mitsubishi uses TO and FROM instructions for writing to or reading from special function modules (any module other than regular I/O extension). The instruction format in ladder is standard, but for the read/written data format you have to see the module manual.

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I love AB's addressing scheme. Be aware that the cards use variable amounts of slot addresses, so being in physical slot 3 doesn't really tell you it's address.

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that's true. check I/O assignment under plc parameters. for example if the card in slot1 is using 32 point and card in slot 2 is using 16point then situation would look like this: slot  points   io_range 1     32        0x00-0x1F   2     16        0x20-0x2F 3    etc. 4 this means that next card would start at 0x30. to read the values from the analog input card you have to: - download manual from www.meau.com and read it (check for buffers) - create init program to setup the card on PLC powerup (configure and enable channels) - create program to read the values from the card (read the buffers) and read the 'conversion_complete' flags - make sure to scale/convert/use the values only when conversion is complete the FROM instruction is looking for 'head' address of the card. this is calculated by dividing start address by 16. for example above where start address for the third card happen to be 0x30, you have to drop the last digit (divide by 16 in hex world) so you get hex value 0x3 and instruction would finally look like FROM h3 BBB MMM NNN where BBB is first buffer address in the block you want to read from MMM plc memory where the copy would end up NNN number of register to be copied So if you want to read 5buffers starting from address 2 (buffers 2,3,4,5,6) and you want to put them into D memory starting ad D22 (22,23,24,25,26) you would use something like FROM h3 k2 D22 k5

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I think the values under plc parameters are there for you to set, and not to report the addresses used by the cards, no? At least in Medoc, I used it to allocate the same about of addresses to all card slots, so I could leave cards out and not change a standard program. This was on an A1S system, and then again, I may be high. It's been years.

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actually you are right, A doesn't support reading I/O map from PLC. looking under parameters would help if the other two slots ware already configured otherwise it is usually simpler to put special card in the first slot just to be able to easier follow the manuals and gain some experience. i would suggest to deer to check out tutorials and older topics in this forum. we had topics like 'transition from AB to mitsubishi' etc. another thing which is a must - get the manuals for every mitsubishi component you plan on using. if you are using GX Developer, get the instruction manuals but first get manual for GX Developer such as ib(na)0800190 (this is for version 7). It explains a lot... One thing that will be very important to learn is how to use buffer monitor. here are some more manuals: IB(NA)66249 - A and Q cpu fundamentals IB(NA)66250 - A CPU common instructions IB(NA)66251 - A and Q CPU dedicated instructions IB(NA)66435 - Programming manual for A1S63ADA IB(NA)68474 - Hardware manual for A1S63ADA All files can be downloaded from Mitsubishi servers such as http://www.meau.com/ US http://www.mitsubishi-automation.de/ Germany ...and don't be shy to ask questions. some things are not straight forward even though they might be mentioned in the manual (lost in translation...).

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