将32位实数转换为2x 16位字节 [英] Converting 32-Bit Real to 2x 16-Bit Bytes

问题描述

我正在尝试通过CAN通信（IFM）发送32位实数，但是CAN通信只接受16位值。

I'm trying to send a 32-Bit Real across a CAN communications (IFM) but the CAN comms only accepts a 16-Bit value.

如果我尝试发送的值超过255，它将重置为0，并继续该模式。因此，我需要将32位的Real值拆分为两个16位的值，然后在通讯的另一端重新组装。

If the value I'm trying to send goes above 255, it resets back to 0 and continues in that pattern. I therefore need to split the 32-Bit Real value in to two 16-Bit values and then reassemble on the other side of the comms.

我似乎不明白

任何帮助将不胜感激

推荐答案

我知道我参加聚会有点晚了，但想将此添加为解决方案。

I know I am a little late to the party but wanted to add this as a solution.

VAR
  rRealVar  :   REAL;
  awWordArray   :   ARRAY[0..1] OF WORD;
  pTemp     :   POINTER TO REAL;
  pTemp2        :   POINTER TO REAL;
END_VAR

// Get a pointer to the REAL variable
pTemp := ADR(rRealVar);

// Get a pointer to the ARRAY base
pTemp2 := ADR(awWordArray);

// Assign the value of the REAL variable into the ARRAY base
pTemp2^ := pTemp^;

(* Index 0 := Bits 15-0
   Index 1 := Bits 31-16

这类似于Felix Keil的答案，但它使用了2个指针变量和单词数组直接检索信息。

This is similar to Felix Keil's answer but it makes use of 2 pointer variables and a word array to retrieve the information directly.

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