Specifications

RMa750 Programming Definitions Monday, 10 July 2000

page 4

A 2 pin header on the amplifier interface is utilised to select which option is appropriate. We will be

supplying the units with a header link in place which will have the amplifier automatically open the

relay.

Once a fault is detected the CNPI/CPI input is held/latched low. The input will remain in this state

until a reset from the control system is detected (via channel 14 on CNPI/.CPI output).

Amplifier Channel Isolated Indication (normally high)

Channels 7 to 12 monitor speaker output relay status.

Channel 7 = Channel 1 of the amplifier

Channel 8 = Channel 2 of the amplifier

Channel 9 = Channel 3 of the amplifier

Channel 10 = Channel 4 of the amplifier

Channel 11 = Channel 5 of the amplifier

Channel 12 = Channel 6 of the amplifier

This facility is used as a feedback indicator to the control system that the speaker output relays have

actually been opened either automatically by the amplifier or by the control system. This could be

useful when switching in another amplifier channel (as back up) to the speaker feed of the isolated

channel.

Fan Speed Detect

Channel 13 (on CNPI/ CPI card) is used to indicate to the system if the cooling fans are on low

speed or at high speed. If the fans are at low speed Channel 13 will be low, If they are at high speed

then Channel 13 will be high. Low will be the default position. If after a period of time the

amplifier was switching to high speed too soon, then this may indicate the need to unblock the air

intake grilles or the load has a fault and is drawing extreme power from the amplifier etc.

Thermal Detect.

Channel 14 is used to indicate if the amplifier has gone thermal. The input will be normally high

and will go low when the amplifier has thermalled.

In the thermalled state all amplifier channels are muted internally by the amplifier. The channels

will remain muted until the heatsink temperatures have reduced by approximately 20

C after which

all channels will automatically un-mute and return to normal operation.