(20) VAR8-ACU operation guide

VAR8-ACU and Variants - Operation, Commissioning, Fault Finding, and Maintenance Guide

21 Diagnostic Tools and Methods

The system has various useful diagnostic features to enable the location of a fault to be pin-pointed during commissioning and for maintenance purposes.

21.1.1 Hardware

The Network Interface Card has a series of diagnostic LEDs. Their functions are annotated on the cover plate silkscreen.

DOWNSTREAM UPSTREAM

The following indicators are available for both UPSTREAM and DOWNSTREAM ports.

LED Function

ACTIVITY

BUS1-FAULT

BUS2-FAULT

BUS3-FAULT

Indicates any data activity on the RS485 port, transmission or reception

Illuminates if the Slave has isolated audio bus-1 because of a fault

Illuminates if the Slave has isolated audio bus-2 because of a fault

Illuminates if the Slave has isolated audio bus-3 because of a fault

21.1.2 Software

The Audio Control Unit provides the diagnostic tools described in the following sections.

21.1.2.1 Current Status of the Health Status of the Network

A quick diagnostic check on the current health of the network is available via the

ConfigurationÆSystemÆNetworkÆDiagnosticsÆLoop-test menu.

Tx shows the number of messages transmitted by the Audio Control Unit round the network loop. Rx shows the number of these messages that it receives back again. If the network is working correctly these two numbers should be equal.

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VAR8-ACU and Variants - Operation, Commissioning, Fault Finding, and Maintenance Guide

The fault code displayed by the Audio Control Unit indicates which channel is affected and where the isolation has occurred and is of the form:

NET-Y/XX AUD RECOVERED

Y= Network Audio Channel (1, 2, 3) on which fault occurred

XX=Address of Slave Unit where isolation occurred

So if the report was NET-3/01 AUD RECOVERED. This would mean that an audio fault has occurred on

Audio Bus-3 between Slaves 1 and 2 and it has been successfully recovered by isolating the faulty segment.

It is also possible to disable the Audio Loop Recovery Mechanism via the following menu. This is useful when fault finding and when commissioning a system.

Menu: ConfigurationÆSystemÆRouterÆMiscÆAudio recovery

21.1.2.3 Data Loop Failure

When a data loop failure occurs the following fault code is always reported at the Audio Control Unit:

INT-01 LOOP FAIL

Because the system instantly recovers communications to all Slaves automatically there may be no other fault reports from which one can diagnose the location of the fault.

To facilitate pinpointing of the faults various diagnostic facilities are available in the

ConfigurationÆSystemÆNetworkÆDiagnostics menu.

The technique is as follows: select incremented when the Slave fails to respond to a message from the Audio Control Unit.

3. If you press SELECT this will clear all counts to zero.

4. The screen displays the Slave addresses from left to right with a counter underneath each one. The count increments every time the Slave is polled and fails to respond. It can quickly be seen which Slaves are failing to respond. These are on one side of the faulty connection.

5. Next, select the Tx-Dir facility and change the direction to DOWNSTREAM ONLY

6. Then select the Slv-t/o (Slave-Timeouts) facility.

7. Press SELECT to clear the count to zero.

8. You can then see which Slaves are failing to respond in the other direction. These are on the other side of the faulty connection.

9. Once the fault is repaired, the Tx-Dir should be returned to BI-DIRECTIONAL. All Slave faults should be cleared via the Audio Control Unit and, finally, the Audio Control Unit faults cleared.

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VAR8-ACU and Variants - Operation, Commissioning, Fault Finding, and Maintenance Guide

When commissioning a system, it is often desirable to temporarily remove one or more configured units from the poll sequence. This may be to avoid broadcasting audio to them, or to prevent partially commissioned units from swamping the system with faults.

The following menu presents a list of slave addresses and the facility to set each to either ‘1’ (include in poll loop) or ‘0’ (exclude from poll loop).

Menu: ConfigurationÆSystemÆNetworkÆDiagnosticsÆPoll-ctrl

21.1.2.5 All Call Mode Control

During installation and commissioning when the Slave Units may not be functional and the ACU goes into All

Call mode, it is desirable to enable normal paging.

The All Call mode can be disabled via the following Audio Control Unit front panel menu.

Menu: ConfigurationÆSystemÆNetworkÆAll-call

The All Call mode is automatically ENABLED when the user logs off, alternatively the user can set the All

Call mode back to ENABLED.

21.2 Other Testing Facilities

During operation when a fault occurs or an announcement is not completed it is desirable to view the current routing status, which is available via the following menu.

Menu: TestÆMonitorÆRouting

Where:

L00 = Nothing currently routed to O/P 1

L04 = Local I/P 4 currently routed to O/P 2

N02 = Network I/P 2 currently routed to O/P 3 etc.

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VAR8-ACU and Variants - Operation, Commissioning, Fault Finding, and Maintenance Guide

This function enables the user to view the physical contact state (operated or not operated) on the Router and on each Remote I/O Unit.

For the Router, access the following menu:

Menu: TestÆMonitorÆContactsÆRouter

For a Remote I/O Unit, access the following menu:

Menu: TestÆMonitorÆContactsÆRemote

Where:

0 = contact open, inactive

1 = contact close, active

Individual input sources can be monitored on the loudspeaker and a simple bargraph via the following menu.

Menu: TestÆMonitorÆAudioÆInputs

Audio monitoring affects only the LCD display of the unit, i.e. all fault-monitoring activities continue to take place in the background. The status of the LEDs and external outputs are unaffected.

The level displayed is dB (FS). This is dBs relative to digital Full Scale. Typically the input gain should be set so that input signal peaks are in the range –10 to –20dB (FS) to allow enough headroom within the Router.

The monitored audio level is adjustable by the rotary encoder. Note that this volume control affects only the monitor audio level and not the level of the alarm sounder, which shares the same amplifier and speaker.

21.2.4 Sounder and Lamp Test

It is possible to perform a test of all LEDs and sounder on the unit front panel via the following menu.

Menu: TestsÆLamps

LEDs are turned off, then on in sequence while the sounder is turned on and off. The menu will be locked during the test. On completion of the test, normal LED and sounder operation resumes.

L

The user can perform the Lamp and Sounder test by pressing the front panel LAMP TEST key.

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