String to Binary

[robotguy21]

Hello, I am trying to convert a incoming string that is in Binary format (See attachment) to a DINT. Any ideas? When I use the STOD command it turns it into in my example 11,110,000 instead of the 16 that I need.

 

[JeremyM]

You will have to translate each byte of the string.

 

[plvlce]

STOD converts from string to decimal without changing the apparent (ie formatted for viewing) value, so unless you start with a string of '16' you will of course not get 16 as a decimal value out.

How have you determined that 16 is the value you should be getting? In binary 16 is 00010000, I don't see where in your StringID that appears.

It seems to me that you do not actually understand the incoming format; from the simple fact that it contains a '4' and a '-' it is clearly not simply binary. What is sending it?

 

[robotguy21]

STOD converts from string to decimal without changing the apparent (ie formatted for viewing) value, so unless you start with a string of '16' you will of course not get 16 as a decimal value out.

How have you determined that 16 is the value you should be getting? In binary 16 is 00010000, I don't see where in your StringID that appears.

It seems to me that you do not actually understand the incoming format; from the simple fact that it contains a '4' and a '-' it is clearly not simply binary. What is sending it?

I misspoke it is 15 instead of 16 on the binary code. This is a part of a long string I am using to know what sample is running.

 

[plvlce]

I misspoke it is 15 instead of 16 on the binary code. This is a part of a long string I am using to know what sample is running.

15 is 1111 in binary.

Again, you need to identify (either from documentation or testing) what the format of the incoming string is -- or more specifically which characters actually correspond to your binary number. Given an expected value of '1111' it could be any 4 characters from the 2nd to the 8th.

Once you know that, you can extract just those with MID; to then convert to an integer is more challenging but could be accomplished eg with an EQU for each character and an OTE for the corresponding bit of the integer.

 

[Ken Roach]

Thanks for the correction.

There isn't a built-in instruction with a selectable radix and/or bit order that will do this conversion for you.

Fortunately it's easy just with EQU and OTE to examine each character of that fixed-length string and set a bit sub-element inside a DINT tag, as long as you are certain which characters of the string represent your encoded value.

Just compare GetStringIDtmp.Data[0] to 49 (ASCII = "1") and set Bit 0, and so on for .Data[0] through .Data[7], to set Bits 0-7.

 

[robotguy21]

Thanks for the correction.

There isn't a built-in instruction with a selectable radix and/or bit order that will do this conversion for you.

Fortunately it's easy just with EQU and OTE to examine each character of that fixed-length string and set a bit sub-element inside a DINT tag, as long as you are certain which characters of the string represent your encoded value.

Just compare GetStringIDtmp.Data[0] to 49 (ASCII = "1") and set Bit 0, and so on for .Data[0] through .Data[7], to set Bits 0-7.

I think I made a work around. I ended up making a AOI that works for what I am doing. Thanks for the help. If anyone ever needs it let me know.