This field specifies the MIB variable or expression on which thresholding is to be performed, in dotted numeric notation, followed by an instance identifier. For example, to perform threshold checking mib-2.interfaces.ifTable.ifEntry.ifInErrors (object ID .1.3.6.1.2.1.2.2.1.14) for interface 1, this field would contain .1.3.6.1.2.1.2.2.1.14.1. To perform threshold checking on all instances of a variable, an asterisk can be used. In the previous example, to perform threshold checking on all interfaces, the object ID .1.3.6.1.2.1.2.2.1.14.* would be entered. The instance ID can also be a non-numeric string, in which case each octet in the string is converted to an object identifier. For example, to threshold on the smMlmSystemFileSystemPercentUsed variable (object ID .1.3.6.1.4.1.2.6.12.2.5.2.1.4) for the /usr directory, .1.3.6.1.4.1.2.6.12.2.5.2.1.4./usr would be placed in this field since the Remote Manager filesystem table uses the directory name as the index. Most of the tables supported by the Remote Manager use a name as an index, so using the character form of the name provides a simple way to specify an instance identifier. Threshold MIB variable expressions can be any expression comprised of local or remote node MIB variables with the following high to low precedence and left to right associativity of operators: () : grouping - : unary minus * : multiplication, / : division, % : remainder + : addition, - : subtraction << : bitwise left shift, >> : bitwise right shift & : bitwise AND ^ : bitwise exclusive OR | : bitwise inclusive OR Expression evaluation/operators are based on standard c program execution. Counter MIB variables default to the delta value, calculated by subtracting the old MIB value from the current MIB value. Integer and gauge MIB variables default to the current value returned. The two functions @delta() and @value() can be used to override the above defaults. Displaystrings can be converted to a real value using the @delta() and @value() functions. Built-in functions available within expressions include: @sum(MIB variable expression, MIB variable expression, ...) - returns the sum of all values. @avg(MIB variable expression, MIB variable expression, ...) - returns the average of all values. @min(MIB variable expression, MIB variable expression, ...) - returns the minimum of all values. @max(MIB variable expression, MIB variable expression, ...) - returns the maximum of all values. @diff(MIB variable expression, MIB variable expression) - returns the positive difference in the two expressions. @delta(MIB variable expression) - uses the delta value calculated by subtracting the last returned MIB variable value from the current MIB variable value. This function can be used to force delta calculations on integer, gauge, and displaystring MIB variables. @value(MIB variable expression) - uses the current MIB variable value. This function can be used to force the use of actual values for counter MIB variables. @numInst(MIB variable expression) - returns the number of instances found for the MIB variable expression. @abs(MIB variable expression) - returns the positive value of the expression. @rand() - returns a random number between 0 and 42949667295. The \ character can be used as an escape character in the object ID to input the special character: period(.). For example: .1.3.6.1.2.1.2.2.1.14.1.\. replaces the \. with the integer 46, the ASCII decimal value for period(.). Agent Policy Manager (APM) uses the special string: {NV_x.x.x.x} as part of the object ID and the periods within the string ARE converted to the ASCII decimal value of 46. In other words, the periods are treated as characters instead of object ID delimiters. When using the Mid-Level Manager, if a name followed by a colon is prepended to the object identifier, it is taken to be an alias for a group of nodes (if defined in the Remote Manager Alias Table) or the name of a remote node. For example, entering aixnm007:1.3.6.1.2.1.2.2.1.14.* will cause threshold checking to be performed on all instances of ifInErrors on machine aixnm007. If aixnm007 is defined in the Alias Table as an alias for a group of machines, threshold checking of these variables will be done for every machine in the group.