USL JSD-100 Manual - Manual (Page 22)

Page 22
6.7 Analog Audio Output Connections
Depending on which analog output module is installed, the JSD-100 provides eight or sixteen main channel outputs
plus HI and VI-N outputs. All outputs are balanced and may drive balanced or unbalanced loads. When driving
unbalanced loads, run two conductor shielded cable and connect the “ – ” terminal of the JSD-100 output to the
low side of the unbalanced load at the load instead of at the JSD-100 to minimize ground loop noise.
Main Audio Outputs
The main audio outputs are on a module that can be replaced from the rear. A variety of output modules are
available, including 8 channel analog, 16 channel analog, and 32 channel AES. Note that the 16 channel analog
output module and the 32 channel AES output module support crossovers. To allow for proper bypass operation, a
passive crossover is included. For full band operation, set all four DIP switches to OFF and set the MID and HIGH
trim pots to full counter-clockwise. Adjust the LOW trim pot for the desired full range bypass audio level.
Remember that the front panel fader also affects output level when in bypass. For bypass operation with
crossovers, see Section 7.5.1. The connections for these output modules are detailed in Appendix A.
HI/VI-N Outputs
The JSD-100 has balanced HI and VI-N outputs that can drive balanced or unbalanced loads. As with other outputs,
the use of twisted pair shielded cable is suggested whether the load is balanced or unbalanced. When driving an
unbalanced load, connect the “ – ” output of the JSD-100 to low side of the unbalanced input at the destination
end of the cable to minimize ground loop noise. The source of audio to drive the HI and VI-N outputs is
configurable on a per-format basis. The VI-N audio output is typically driven by AES input 8. The HI audio output
can be driven from AES inputs 7 or 15, or from a main audio mix. The JSD-100 includes an automatic HI fallback.
The HI output is typically configured for AES input 7 to take advantage of the discrete dialog centric audio track
delivered with much digital cinema content. If no audio is present on the selected HI source, the JSD-100 will
automatically use an LCR mix. The USL supplied ferrite block should be clipped on to the cables adjacent to the
connectors to comply with FCC and CE emission requirements. See Appendix A for pin out information.
6.8 Automation Interface
The JSD-100 includes the traditional parallel automation interface plus RS-232 and Ethernet.
Parallel Interface
Pins 1 through 10 of the DB25F automation connector are “control” pins that accept contact closure or open
collector pulses to ground to select formats. On a format change, the corresponding pin is also pulsed low allowing
this interface to drive other equipment. Pulsing pin 11 low toggles the mute state. Pins 14 through 24 are “status”
pins. One of the pins 14 through 23 is pulled low continuously by the JSD-100 to indicate the selected format.
These pins could drive LEDs with a 470 ohm series resistor to provide a remote format indication. The JSD-100
pulls pin 24 low when the system is muted. Pins 1 through 11 are internally pulled up to +8.4V. They each source
400uA when grounded. A pin needs to be pulled below 2.6V for 10ms or more for the JSD-100 to recognize it as
low. On a format change, the JSD-100 pulls the appropriate pin low for 500ms. +5V at 100mA is available on pin 13
to drive external LEDs or relays. The individual control and status outputs can sink up to 150mA with an open
circuit voltage of +12VDC for inductive loads like relays or +24V for non-inductive loads (indicator lamps, etc.). Pin
12 is the “automation return.” Use this as the low side of switches and indicators instead of using chassis ground.
It is ground through a 10 ohm resistor to limit ground loop current. The USL supplied ferrite block should be
clipped on to the cables adjacent to the connectors to comply with FCC and CE emission requirements. See
Appendix A for pin out information.
RS-232 Interface
The RS-232 interface appears on a DE9F connector on the rear panel. The connector is wired as a DCE device. A
command interpreter accepts ASCII commands (described in Appendix B) over the RS-232 and Ethernet interfaces.
The RS-232 port operates at 38.4kbps, 8N1 (8 data bits, no parity, 1 stop bit), hardware handshake. In most
situations, no handshake is required, and the RTS and CTS pins can be left open. The USL supplied ferrite block
should be clipped on to the cables adjacent to the connectors to comply with FCC and CE emission requirements.
See Appendix A for the connector pin out.