Trap number simply tells you where you're at on the list of the local SNMP Agent's traps. Click "Next" and "Prev" to scroll through the list. To advance directly to a specific trap trigger, enter the desired number in the "Showing" box, then click Update.

Traps can only be generated for variables that are delcared in the Local MIB. Select the MIB branch and table index to be tested. The local object referenced in the MIB will be tested to see whether this trap is true or false. A variable not found in the Local MIB cannot generate traps.

The object found in the MIB branch, at the table index given, is displayed for reference as "Looking up...". To change this object, go to that MIB branch and table index, and change the MIB definition, or select a different branch and/or table index.

Select a comparison or test. Enter the value against which the MIB variable should be tested, or alternately, enter a local object number that will contain the value against which the MIB variable should be tested. If object is "none", then the fixed value will be used. If a valid object number is given, then the fixed value is disregarded.

Quaifications are optional, and enabled only when values are nonzero. How hysteresis is applied depends on the comparison. For a test that becomes true if greater than, the test will not return to false until the local object is less than the test value by a margin of at least this hysteresis value. If a test becomes true if less than, it will not return to false until the local object is greater than the test value by a margin of at least this hysteresis value.

Special test types: "Deviates from" will test against the value given, and use Hysteresis as the margin of deviation. This is effectively a "greater than or less than" test for deviation from a setpoint. "Changes by" will become true each time the given variable changes by the value given, and Hysteresis has no effect on this test. If "Changes by" references a value of zero, then this becomes a special test whereby the event is true any time something in the system updates the variable. A "changes by zero" should not be used when the variable is continuously read from a slave device since this will result in continuous traps.

On time and off time, if specified, determine how long the condition must be true (on time) or false (off time) before the true or false response is actually taken. Times are given in HH:MM:SS format (hours, minutes, seconds).

Check "Send if True" and/or "Send if False" to indicate when traps should be sent. Enter a repeat count if the trap should be repeated. If repeat count is zero, the trap will be sent one time. If repeat count is 1, the trap will be sent 2 times, and so on. The interval between traps will be the Repeat Time in seconds. Enter -1 for trap repeat count if the trap should simply repeat indefinitely at the Repeat Time interval. A repeat count of -1 for "Send if True" is acceptable. A repeat count of -1 for "Send if False" will be treated as no repeat since indefinite repeating of non-true events is ill-advised.

One of the varbinds in the trap message is an arbitrary ASCII character string, sent as an ASN Octet string. The "True" message will be sent when the trap event is true, and the "False" message will be sent when the trap event is false.

To delete the rule shown, click Delete. To insert a new rule before the rule displayed, click Insert. To add a rule to the end of the list, click Next when at the end of the list, enter new rule, and click Update. The number of rules enabled simply limits the scope of rule review so that you do not have to review a lot of unused rules. If the displayed rules are used up and you need more, increase the enabled number.

IMPORTANT: If deleting rules shortens the list of traps, a MIB walk will still show the original number of traps. To reload the SNMP tables with a shorter list of traps, delete the traps as needed, save the configuration to the boot configuration XML file, then restart the gateway. This will force SNMP to reload the new shorter list.