Biamp Vocia LSI-16 Manual De Operación página 11


TTL: 2V to 5V logic sense. To enable a TTL input, apply a TTL logic high with respect to Isolated
Ground. This can be configured in software to detect a low to high or high to low transition.

High Range: To enable a High Range input, use a dry contact to switch the input to a voltage of
24V DC with respect to Isolated Ground. This can be configured in software to detect a low to high
or high to low transition.

High Range – Monitored: This circuit is implemented in the same way as the 'High Range' input.
This option allows monitoring of each input for short to ground and open circuit. In order to sense
open circuit, a terminating resistor must be fitted between each Control Input and Isolated Ground
at the far end of the input circuit being sensed. The IM-16 will sense open circuits on the line
between its input and the terminating resistor. Shorts to Isolated Ground are sensed across the
entire line being monitored. A 6k8Ω resistor should be used for each input. If a monitoring fault is
detected on any input the logic state or transitions on that input will be ignored until the fault is
cleared. High Range – Monitored inputs require a low to high transition to enable the input
(transition direction not configurable).

Contact Closure: Uses a dry contact without the requirement to use the 24V DC with respect to
Isolated Ground.
System Fault Relay Connection
This relay is activated when the LSI-16/LSI-16e is fully operational. It may be used for informing external
devices about the LSI-16/LSI-16e's operating conditions or sounding an alarm that indicates the LSI-
16/LSI-16e is not functioning reliably.
RS232
The RS232 port can be used to send VTP commands to the LSI-16/LSI-16e and monitor Vocia system
health. Please see the software Help File for details.
24V DC Connector and LED
This is the primary (main) power supply input for the LSI-16 and as such must be fed from a suitable
source of 24V DC capable of 15 watts (625mA). The 24V DC supply has to be sourced separately. In
typical installations, this supply will be provided from a power supply compliant with local norms and
required standards (typically battery-backed). The adjacent LED indicates the presence of power.
Sourcing 24V DC for High Range Inputs
The High Range logic inputs should be driven from a contact closure (relay or switch) in connected
equipment. The High Range inputs expect to sense a transition from low-state voltage (0-11V) to high-
state voltage (12-30V). A 24V Logic High Reference output voltage is provided by the IM-16 for this
purpose. Alternatively an external 24V reference may be used. If an external supply is used, the ground
connection of the external supply must be wired to the IM-16 Isolated Ground.
IP30 Compliance
The LSI-16 is designed for ingress protection to the IP30 standard. In order to maintain this compliance,
any unused terminal connectors on the back of the unit must be fitted with the supplied terminal blocks.