Reading multiple addresses from MC Protocol (Mitsubishi FX PLC)

[Steve-Mcl]

@Jayeshpitale1

i need to know that how to find bytes offset and index offset

Do you know what a 16 bit value is?

Do you know what a BYTE is?

1 MC READ value is 16 bit AKA 2 bytes.

therefore:

• If you get 3 16bit values [xxxx, yyyy, zzzz] then xxxx is bytes 0 & 1, yyyy is bytes 2 & 3, and so on.
• if you read D990,50, then D990 is byte 0 & 1, D991 is bytes 2 & 3 ... D1024 is bytes 68 & 69, and so on.
• if you read D1040,50, then D1040 is byte 0 & 1, D1041 is bytes 2 & 3 ... and so on.

It is simple maths.

Byte Offset = (Address - Start Address) * 2

e.g.
Address: D1048
Start Address: D1040
Byte Offset = (1048 - 1040) * 2 = 16

Read this again:

@Steve-Mcl

That said, i can see you have entered the address D990. That will READ only 1 WORD of data!. How do you expect to parse things like temperatureSetting which is at D993?

Let me explain the point of this all.

1. You want to READ from the PLC many things at once to make your code easier to maintain, get best performance, get good consistent data
2. So we read 99 16 bit integers starting from D990
3. Remember, D registers are 16 bit AKA 2 bytes wide
4. That means D990 value is at index 0 (offset byte 0)
5. That means D991 value is at index 1 (offset byte 2)
6. That means D992 value is at index 2 (offset byte 4)
7. That means D993 value is at index 3 (offset byte 6)