Honeywell UMC800 Reference Guide

Function Blocks
Function Block Reference Guide 3/9996
2.34 MATH Function Block,
continued
Output
ERR
= ON if block detects an error on any of the following operations:
•
division by 0
•
fractional root of a negative number (for example: -2**0.5)
•
zero to the zero power
•
LOG10 or LN of a negative number or 0
•
result of x^y is greater than 1.7E + 308.
•
result of EXP (x) is greater than 3.4E + 308 or less than 3.4E -308.
Note 1
:
For the above rules, groups of constants will be combined and treated as one constant.
Note 2
:
Any number less than or equal to 3.4E -308 is considered 0.
OUT
= Calculated Output.
ATTENTION — Use only the following words and characters in equations
–
+; -; *; /: ^; EXP; LOG10; Ln; Negative (Unary minus);
– ' ' Blank space (ignored)
– 'a' . . 'h' Variables (operand) either a constant or tag
– ( ), [ ], { } Parentheses - 3 types
• A left parenthesis must have a matching right parenthesis.
• The matching parenthesis must be the same type - e.g., ( ), [ ], or { }.
• Parentheses may be nested to any depth.
• Infix operators: +, -, *, /, ^ must have a left and right operand.
• If the '-' operator only has a right operand, it is interpreted as the Unary minus.
• Function operators: EXP, LOG10, Ln must have an operand to the right, and the operand must be
enclosed in parentheses;
Example: EXP(A), LOG10(b), LN(c).
Block Properties
Double click on the function block to access the
function block properties dialog box.
Block Order (Read Only)
You can change the assigned execution order
number by selecting “Execution Order” in the
“Configure” menu and arrange the order to suit
your control strategy.
Configuration Parameters
You must configure the MATH function Block
parameters to the desired value or selection that
matches your operating requirements.
Table 2-29
describes the
parameters and the
value or selection.
Continued next page

Honeywell UMC800 Specifications

General

Brand	Honeywell
Model	UMC800
Category	Controller
Language	English