Attero Tech SquawkBox - Manual (Page 13)

SquawkBox
User Manual
 Attero Tech LLC 2014 Page 9 614-00007-04
5.2 – Override Test
Figure 6 - Override Test Form
The override test form allows the user to test the override settings on a SquawkBox system. It can be used to generate full
system or partial system overrides as required. Select the EMERGENCY option for a full system override or select the blank
option for a partial system override. If a partial system override is required, one or more of the Group check boxes will also
need to be checked. These refer to which groups of SquawkBox units should be included in the override.
The override can also include substitute values that can be used instead of each devices’ own override defaults. Initially, the
override test is setup to use each SquawkBoxes default override settings with the on-screen values taken from the set-up of
the device whose configuration is being edited. The substitute values are applied to each SquawkBox that the override
affects in place of the defaults override settings when the override is active.
*Note:
The substitute values are only temporary and valid as long as the override lasts. The default override values of those
SquawkBoxes that are overridden are not changed.
If values that differ from the defaults are required, prior to starting the override test, clear the “Use Default” box for the
setting to be substituted and then change the setting to the required value.
To start the override test, click the start button. The override will remain active until the stop button is pressed. The
override will also terminate if the form is closed.
*Note:
A SquawkBox that is already in overridden cannot be overridden again. If a second override occurs, the values from
the initial override will be retained. However, any unit in override WILL drop out of override it is sees the stop packet. If this
packet is a broadcast, such as used by this test facility, any unit in override will drop out irrespective of the number of
overrides active on the system.
5.3 – Activating the Override
The override is activated by sending a UDP packet to port 4120 on one or more SquawkBox devices from an Ethernet device
(such as a PC). The packet sent contains a small amount of data. This data includes the type and scale of the override as
well as optional parameters that can be used as a substitute for the devices’ own override default settings. The packet must
contain at least the following fixed length fields:
Field Type Description
Tag 9 char +
null A null terminated character string. This should either be blank (first character a null) for a
general override or set to “EMERGENCY” for a system-wide override of all units.
groupMask 16-bit 16-bit mask, one bit per group. Group 1 is the LSB, group. Group 16 is the MSB.
For a system-wide override, set the tag field to “EMERGENCY” and broadcast the packet to all units by using an appropriate
broadcast destination IP address for the network in use. If the tag field is set to EMERGENCY, a group mask is not required.