somebody know if there are some instruction or short method in RsLogix500 to convert DEC to HEX and pass it to ST file
e.g. (N7) 123d ---> 7Bh (ST)

or i need to apply the typical algorism in lader logix operation by operation?

DIVISION / RESULT / REMAINDER (in HEX)
123 / 16______7_____(0.6875)(16)=11=B
7 / 16________0_____(0.4375)(16)=7

ANSWER 7B

Thanks

I'm not 100% sure what you are asking.
You want to convert a value in N7 into a Hexadecimal string. Is the value in N7 'normal' or is it binary coded decimal (BCD)?
Does this mean you only want to convert into 4 Hexadecimal digits (the maximum value in 16 bits)
What about negative numbers - are they treated as positive?

There are 4 instructions which may be of use to you (probably not though)
TOD which converts a 16bit value to a 16bit binary coded decimal value (BCD)
FRD which does the opposite of above
AIC which converts a 16bit value into a decimal string and
ACI which does the opposite.

It's not the most pretty code but this converts where N7:0=123 to ST9:0="7B" and uses N7:1 and N7:2 as temp stores.

SOR BST AND N7:0 15 N7:1 NXB ADD N7:1 48 N7:1 NXB GEQ N7:1 58 ADD N7:1 7 N7:1 BND EOR SOR BST AND N7:0 240 N7:2 NXB DIV N7:2 16 N7:2 NXB ADD N7:2 48 N7:2 NXB GEQ N7:2 58 ADD N7:2 7 N7:2 BND EOR SOR BST SWP #N7:2 1 NXB OR N7:1 N7:2 N7:1 NXB MOV N7:1 ST9:0.DATA[0] NXB MOV 2 ST9:0.LEN BND EOR

converts the lower byte (0-255) from N7:0 to a 2 digit hex value in ST9:0 (with trailing zero).

If you repeat the code after a SWP instruction to swap the high byte of N7:0 to the low byte you can acheive a 4 digit hex value (16 bits) and if your N7:0 is BCD then do an FRD instruction at the start.

Hope this helps (although it may hurt)