Crest Audio NDP-ENG ETHERNET NEXSYS GATEWAY User manual

Product Information
Crest Audio’s Ethernet NexSys Gateway is the easy way to incor-
porate computer control into your existing Ethernet network.
The figure below shows a typical NexSys network using 2 Gate-
ways for controlling more than 32 amplifiers. The ethernet inter-
face speed is 10Mbit and uses standard CAT5 cable. Systems can
contain up to 240 Gateways.
The maximum number of amplifiers connected to one NexSys bus
is limited by the NexSys Network’s adherence to the “ANSI TIA/
EIA-485“ recommended standard. A NexSys bus, which consists
of multiple amps connected by a length of twisted-pair cable with
two terminating resistors, is limited by RS-485 to a maximum of 32
amplifiers. The recommended twisted-pair cable for this bus is
Belden 8442. The maximum length of this bus is 4000 feet.
The gateway can take advantage of existing network cabling with
no need to install seperate cabling just for amplifier control. A real
cost savings in large installations.
Programmable Control I/O
Eightprogrammablecontrolportsareavailableonthegateway.They
can serve as either inputs or outputs. When configured as an input,
the gateway can sense a switch closure, a variable DC voltage, or a
3-contact potentiometer. When configured as an output, the gate-
way can drive a TTL level signal. NexSys contains a utility called
Event Scheduler that allows the NexSys software to react to and
generate control for exernal devices. This utility is very compre-
hensive, easy to use, and extremely powerful..
Crest Audio Ethernet NexSys Gateways are manufactured in the
United States, using only the highest quality selected components
Features
• One RJ45 connector for 10Mbit Ethernet connectivity of
NexSys network with up to 240 Gateways allowed in a system.
• Electrically isolated RS-485 NexSys bus supporting up to 32
NexSys devices.
• Eight user-programmable control I/O ports.
• Front panel power switch, Ethernet link, NexSys data and power
status indicators.
• Rear panel indicators for NexSys data and Ethernet link status
• IEC power receptacle
• 1 rack unit high; width and depth are the same as Crest Audio’s
CK family of Power Processing amplifiers
• Easy to configure using NexSys software
• Five year warranty
NDP-ENG ETHERNET NEXSYS GATEWAY
Up to 240
NDP-ENG’s Up to 32
NexSys Devices
NexSys RS485
network 1
Amplifier
Amplifier
Amplifier
NDP-ENG
Ethernet
network
NDP-ENG
Amplifier
Amplifier
NexSys RS485
network 2
Up to 32
NexSys Devices
Ethernet
device
Ethernet
device

Electrical Specifications
AC Line Current AG Maximum: 165 mA., @ 120V
AG Typically: 65 mA., @ 120V
EW Maximum: 100 mA., @ 240V
EW Typically: 40 mA., @ 240V
NexSys Interface One pair NexSys bus connectors,
electrically isolated, on standard
two wire RS-485, single unshield-
ed twisted pair, RJ45 Ethernet net-
work connector, DB-9 RS-232
connector
I/O Connector Function pin 1: 470 Ohm pullup to +5V
pin 2: I/O
pin 3: selectable reference-circuit
ground (factory); or user reference
(pin 3 ground selection globally
configures all 8 control I/O ports)
I/O Input Voltage Range 0 to 8 V
I/O Max Sink Current 80 mA per output, 500 mA total
I/O Breakdown Voltage 40V
No internal clamp diodes provided on I/O
NexSys is a registered trademark of Crest Audio Inc. Crest Audio reserves
the right to make improvements in manufacturing or design which may
affect specification. Crest Audio specification literature is available in
downloadablePDFformat;visitourwebsiteathttp://www.crestaudio.com.
2000 Crest Audio Inc.
Crest Audio Inc.
100 Eisenhower Drive
Paramus, NJ 07652 USA
TEL:[phone] FAX:[phone]
http://www.crestaudio.com
v. 1.2 11/21/2000
A44000082
NDP-ENG ETHERNET NEXSYS GATEWAY
SPECIFICATIONS
Block Diagrams
Pin 1 - +5 V
Pin 1 - +5 V
Pin 2 - (0-8V Max)
Pin3 -Ground
Pin 2 - (0 or 5V)
Pin3 -Ground
INPUTS
OUTPUTS
Control
I/O OPTOPOT
CLOSURE
0 - 8V
OPTOLEDTTL
+V
RELAY
address
select switches
NexSys
bus conn.
data
LED
microprocessormicroprocessor microprocessor
microprocessor NexSys RS-485
network interface
10Mbit ethernet
Interface
NexSys
bus conn.
RJ45 conn.
RS-232
LED
RS-232 conn.
RS 232
interface
ethernet link
LED
flash
control i/o
470
A/D
+5
8 X
0
8
1
9
2
A
3
B
4
C
5
D
6
E
7
F
0
8
1
9
2
A
3
B
4
C
5
D
6
E
7
F
Hi
Lo
RS-232
Serial
Data Ethernet
Link
Ethernet
Address
65mA max.
Baud Rate
0 - 1200
1-2400
2-4800
3-9600
4-19.2k
Control
I/O
Data
NDP-ENG
100 Eisenhower Drive
Paramus,New Jersey 07652 USA
www.crestaudio.com
NexSys Network 1234
5678
+Ð+Ð
Control I/O Configuration
Pin 2:
Pin 3:
Pin 1:
I nput (0-8 V M ax) or
L ogic O utput (0V or 5V)
G round
5 V olts DC ,with
pull-up resistor
Architect’s & Engineer’s Specification NDP-ENG
The network gateway shall contain one RJ-45 Ethernet network connection and one electrically isolated
Crest Audio NexSys bus. Primary communications to the computer shall be through standard CAT5 Ethernet
cabling. The NexSys bus shall provide access to as many as 32 additional NexSys network nodes. Any node
on the NexSys network shall be accessible to the controlling computer through the gateway. Each NexSys bus
shall conform with RS485 electrical serial protocol.
The gateway shall poll the status of each node on the NexSys network independently from the controlling
computer. The gateway shall also send commands to nodes on the NexSys network as dictated by the control-
ling computer system.
The network gateway shall contain eight programmable control ports to accommadate external inputs to
NexSys via switch closure, variable DC voltage, or 3-contact potentiometers. The control ports shall also
have TTL outputs and relay-driving outputs available to control external devices from NexSys.
The front panel shall include an on/off power switch and LEDs to indicate power (active), NexSys data
(present), and EtherNet link (present). The rear panel shall be fitted with three rotary switches, two with the
purpose of setting NexSys data bus addresses to the gateway, the remaining switch sets the mode and baud
rate of the serial connection. The serial connection shall be present on a female DB-9 connector and NexSys
network access shall be through two 5mm, 3-pin, Phoenix COMBICONâ connectors. Programmable control
I/O shall be on eight similar connecters. There shall be three LEDs present on the rear of the unit, these
indicate NexSys data, serial data ,and Ethernet link.
An IEC AC mains socket shall be provided on the rear panel. 120V and 220V versions shall be available. A
single AC mains cord having an appropriate plug for the intended operating voltage shall be provided. Dimen-
sions shall be 19” (483mm) wide, 1.75” (44mm) high, and 17.13” (435mm) deep. The network gateway shall
be designated the Crest Audio model NDP-ENG.