What does the battery inside the Mastermind do? | What does the coloured bands on the Mastermind BNC connectors signify? | Why does the front panel show failures but no LEDs are lit when I pull the panel down?
If a signal is routed through the Mastermind Changeover unit, a short disturbance in signal of around 200ms is considered normal operation. The changeover element is a mechanical relay: this is by design, to give a failsafe operation should any kind of power failure occur to the changeover unit. With a relay, there will inevitably be a break in the output which when measured is around 200ms.
This is most commonly caused by having an unterminated output on the B&B option card. An easy test is to replace the output cable on the Mastermind with a 75 Ohm termination and check to see if the fault indication clears. If fail indicator is now off, then the output cable is unterminated somewhere further down the chain.
If the failure still shows, then you may have a genuinely faulty option card and should contact Trilogy support.
The batteries inside the Mastermind are only used to drive the alarm in the event of a mains power failure to the unit. To enable the batteries to drive this alarm the battery switch is set to ‘ON’.
In the event of a power failure, if the alarm switch is set to ‘Buzzer’ the internal alarm buzzer will sound or if the alarm switch is set to ‘LED’ the global fail LED will light.
Under normal operating conditions the Battery switch should be set to ON to enable the trickle charging of the batteries from the mains supply. If the battery switch is set to ‘OFF’ the batteries are no longer being charged.
To help identify which module type is installed, a coloured plastic band is fitted to the middle BNC of each module. See the table below for the details.
The front panel acts will show a latched fail indication after a failure has been detected. Therefore, if the fault is rectified or intermittent in nature, you will still get a visual indication that a failure has occurred at some point since the last reset.
A common cause for this is rapid removal and re-insertion of an input, or a change of output termination. A failure of downstream equipment may also cause this condition, as the Mastermind will act as though there is a failure on both A & B channels. In this case both channels will report as failed on the front panel and the unit will not changeover.
In all these cases, pressing the reset button should restore the unit to its working state. If it fails again immediately then the system needs investigating for a current fault.