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Comparison Instructions

Comparison instructions compare two word parameters and output the Boolean result to the logic stack.

Instruction	Description	# Params
ANDE	AND if parm1 equals param2	2
ANDGE	AND if parm1 >= parm2	2
ANDGT	AND if parm1 > parm2	2
ANDLE	AND if parm1 <= parm2	2
ANDLT	AND if parm1 < parm2	2
ANDNE	AND if parm1 is not equal to parm2	2
ORE	OR if parm1 equals parm2	2
ORGE	OR if parm1 >= parm2	2
ORGT	OR if parm1 > parm2	2
ORLE	OR if parm1 <= parm2	2
ORLT	OR if parm1 < parm2	2
ORNE	OR if parm1 is not equal to parm2	2
STRE	STR if parm1 equals parm2	2
STRGE	STR if parm1 >= parm2	2
STRGT	STR if parm1 > parm2	2
STRLE	STR if parm1 <= parm2	2
STRLT	STR if parm1 < parm2	2
STRNE	STR if parm1 is not equal to parm2	2

All comparison instructions take two explicit parameters and output their result to the logic stack. Each parameter is a word register or constant.

There are three categories of comparison instruction: AND, OR, and STORE. Each of these operates in a manner similar to to the corresponding Boolean input instructions, with the exception that they apply the Boolean result of the comparison operation to to top of the logic stack.

For any comparison operation, both parameters must be compatible with each other. Parameters are compatible if they are both within the same compatibility group. The compatibility groups are defined as follows:

Signed numeric - DS, DD, DF, TD, CTD, SD, KInt, KDInt, KF, XS, YS
Unsigned numeric (hex) - DH, XD, YD. KHex
Text - TXT, KTxtChar, KTxtStr

The type and address abbreviations are defined in the section on addresses and constants.

If one parameter is a string constant (e.g. "abc123"), and the other is a text register, the string constant will be compared to the series of text registers beginning at the register specified. The comparison will be on a character by character basis, such that the comparison will fail at the first character that does not meet the comparison criteria.

For example, if the string "hijklanop" is compared to to see if it is greater that a series of registers containing "abcdefghi", the comparison will fail on the sixth character because "a" is not greater than "f".

Example:


	// Compare signed numbers.
	NETWORK 1
	STRE DS1 DS2
	ANDGT 123 DD10
	ORLE DF20 123.876
	ORGE DF5 DS3
	ANDLT 93 CTD3
	OUT Y1
	
	// Compare unsigned (hex) numbers.
	NETWORK 2
	STNE 123fh DH52
	ANDGE YD4 DH2
	SET C20
	
	// Compare text.
	NETWORK 3
	STR X3
	ANDE TXT5 TXT10
	ORGE "A" TXT12
	ANDE "pass" TXT50 
	OUT C35

Ladder Examples

The following shows examples in ladder format. Each example shows the IL code as comments, followed by the ladder equivalent.

boolean compare example 1 boolean compare example 2 boolean compare example 3