Kramer VP-23N User manual

Kramer Electronics, Ltd.
USER MANUAL
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Model:
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VP-23N
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Presentation Switcher 
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Contents
i
Contents
1 Introduction 1
2 Getting Started 1
2.1 Quick Start 2
3 Overview 3
3.1 Shielded Twisted Pair (STP) / Unshielded Twisted Pair (UTP) 3
3.2 About the VP-23N 3
3.3 Recommendations for Achieving the Best Performance 4
3.4 Terminology Used in this User Manual 5
4 Your Presentation Switcher 5
5 Installing the VP-23N in a Rack 11
6 Connecting the VP-23N Presentation Switcher 12
6.1 Connecting the VP-23N Rear Panel 12
6.2 Wiring the CAT 5 LINE OUT RJ-45 Connector 15
6.3 Connecting the Balanced/Unbalanced Stereo Audio Input/Output 16
6.4 Connecting a PC 17
6.5 Connecting via RS-485 17
6.6 Controlling via ETHERNET 18
6.6.1 Connecting the ETHERNET Port directly to a PC (Crossover Cable) 19
6.6.2 Connecting the ETHERNET Port via a Network Hub (Straight-Through Cable) 20
6.6.3 Control Configuration via the Ethernet Port 21
6.7 Controlling via RS-232 and RS-485 21
6.8 Dipswitch Settings 23
6.8.1 Setting the Machine # Dipswitches 23
7 Operating Your Switcher 24
7.1 The Front Panel Buttons 24
7.2 The Independent Switchers Mode 25
7.3 The Master Audio Mode 26
7.4 Using the Infra-red Remote Controller 28
8 Flash Memory Upgrade 28
8.1 Downloading from the Internet 28
8.2 Connecting the PC to the RS-232 Port 29
8.3 Upgrading the Firmware 29
9 Technical Specifications 34
10 Hex Table 35
10.1 Audio Gain Control Hex Tables 35
11 Communication Protocol 36

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Contents
ii
Figures
Figure 1: VP-23N Presentation Switcher – Front View 6
Figure 2: VP-23N Presentation Switcher – Rear View 8
Figure 3: VP-23N Presentation Switcher– Underside View 10
Figure 4: Connecting the VP-23N Presentation Switcher 14
Figure 5: CAT 5 PINOUT 15
Figure 6: Connecting a Balanced Stereo Audio Input/Output 16
Figure 7: Connecting an Unbalanced Stereo Audio Input 16
Figure 8: Connecting an Unbalanced Stereo Audio Output 16
Figure 9: Connecting a PC without using a Null-modem Adapter 17
Figure 10: Controlling via RS-485 (for example, using an RC-3000) 18
Figure 11: RJ-45 PINOUT 19
Figure 12: Local Area Connection Properties Window 20
Figure 13: Internet Protocol (TCP/IP) Properties Window 20
Figure 14: Control Configuration via RS-232 and RS-485 22
Figure 15: Default Dipswitch Settings 23
Figure 16: Separate Switcher Mode 26
Figure 17: Switching in the Master Audio Mode 27
Figure 18: Splash Screen 29
Figure 19: Atmel – Flip Window 30
Figure 20: Device Selection Window 30
Figure 21: Selecting the Device from the Selection Window 31
Figure 22: Loading the Hex 31
Figure 23: RS-232 Window 32
Figure 24: Atmel – Flip Window (Connected) 32
Figure 25: Atmel – Flip Window (Operation Completed) 33
Tables
Table 1: Terminology Used in this User Manual 5
Table 2: Front Panel VP-23N Presentation Switcher Features 7
Table 3: Rear Panel VP-23N Presentation Switcher Features 9
Table 4: VP-23N Underside Panel Feature 10
Table 5: CAT 5 PINOUT 15
Table 6: Crossover Cable RJ-45 PINOUT 19
Table 7: Straight-through Cable RJ-45 PINOUT 21
Table 8: Dipswitch Settings 23
Table 9: Machine # Dipswitch Settings 23
Table 10: Technical Specifications of the VP-23N Presentation Switcher 34
Table 11: VP-23N Hex Table 35
Table 12: VP-23N Master Audio Selector Hex Table 35
Table 13: Set the Audio Output Gain Control for the Groups 35
Table 14: Set the Audio Output Gain Control for the Microphone 35
Table 15: Set the Audio Output Gain Control for the Master Audio 36
Table 16: Increase or Decrease the Audio Output Gain by One Step 36
Table 17: Protocol Definitions 36
Table 18: Instruction Codes 37

Introduction
1
1 Introduction
Welcome to Kramer Electronics! Since 1981, Kramer Electronics has been
providing a world of unique, creative, and affordable solutions to the vast
range of problems that confront the video, audio, and presentation
professional on a daily basis. In recent years, we have redesigned and
upgraded most of our line, making the best even better! Our 500-plus
different models now appear in eight groups
1
that are clearly defined by
function.
Congratulations on purchasing your Kramer VP-23N Presentation
Switcher, which is ideal for presentation and conference room systems,
production studios, rental and staging.
The package includes the following items:
VP-23N Presentation Switcher
Windows®-based Kramer control software
Windows®-based Configuration Manager XPort software and
Com Port Redirector
Null-modem adapter and power cord
2
Kramer RC-IR2 Infra-Red Remote Control Transmitter
(including the required battery and a separate user manual
4
)
This user manual
3
2 Getting Started
We recommend that you:
Unpack the equipment carefully and save the original box and
packaging materials for possible future shipment
Review the contents of this user manual
Use Kramer high performance high resolution cables
4
1 GROUP 1: Distribution Amplifiers; GROUP 2: Video and Audio Switchers, Matrix Switchers and Controllers; GROUP 3:
Video, Audio, VGA/XGA Processors; GROUP 4: Interfaces and Sync Processors; GROUP 5: Twisted Pair Interfaces;
GROUP 6: Accessories and Rack Adapters; GROUP 7: Scan Converters and Scalers; and GROUP 8: Cables and Connectors
2 We recommend that you use only the power cord that is supplied with this machine
3 Download up-to-date Kramer user manuals from our Web site at http://www.kramerelectronics.com
4 The complete list of Kramer cables is on our Web site at http://www.kramerelectronics.com

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Getting Started
2
2.1 Quick Start
This quick start chart summarizes the basic setup and operation steps.

Overview
3
3 Overview
This section describes:
Using shielded twisted pair (STP)/unshielded twisted pair (UTP), see
section 3.1
A summary of the VP-23N, see section 3.2
Recommendations for achieving the best performance, see section 3.3
The terminology used in this user manual, see section 3.4
3.1 Shielded Twisted Pair (STP) / Unshielded Twisted Pair (UTP)
The decision whether to use shielded twisted pair (STP) cable or unshielded
twisted pair (UTP) cable depends on the nature of the application.
It is recommended that in applications with high interference, shielded
twisted pair (STP) cable will give better results. However, the shield itself
does create a capacitance that degrades the frequency response of the
machines. For shorter distances, of 50m or so, shielded twisted pair (STP)
cable is preferred because it provides protection from interference
(degradation is non apparent).
For a long range application, unshielded twisted pair (UTP) cable is
preferred. However, the unshielded twisted pair (UTP) cable should be
installed far away from electric cables, motors etc., which are prone to create
electrical interference.
Some Kramer twisted pair products include the Power Connect feature
1
.
The VP-23N does not have this feature.
3.2 About the VP-23N
The VP-23N is a high quality one-box presentation switcher, which
includes three independent 4x1 audio/video switchers and a master audio
switcher. It combines the functions of a 4x1 switcher for composite video
and audio, a 4x1 switcher for s-Video and audio, and a 4x1 switcher for
computer graphics (VGA/UXGA) signals with audio, as well as the master
audio switcher that routes one of the pre-selected audio inputs (from these
three switchers) to two separate outputs.
1 The Power Connect feature lets you power a transmitter / receiver system by connecting just one power adapter to either the
transmitter or the receiver. The other unit is fed over the same CAT 5 cable. The Power Connect feature applies as long as the
CAT 5 cable is heavy gauge cable (that is, it can carry power). The distance does not exceed 50 meters on standard cable. For
a distance of 100 meters, separate power supplies must be connected to the transmitter and to the receiver simultaneously,
unless using heavy gauge CAT 5 cable

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Overview
4
In addition, the VP-23N features:
VGA/UXGA video bandwidth of 350MHz to ensure transparent
performance even in the most critical applications, and is HDTV
compatible
Composite/SDI video bandwidth of 650MHz, an s-Video
bandwidth of 385MHz, and a CAT 5 output capable of handling
resolutions up to UXGA
16 selector buttons, digital microphone input level control and
digital master audio level control
A microphone talk-over mode (the microphone input signal lowers
the line audio output level when the connected microphone detects
sound)
A CAT 5 output, with a transmission range of more than 300 feet
(over 100 meters) that transmits XGA signals to a remote acceptor
via a receiver
An internal 5-Watt per channel (24kHz, -3dB), power amplifier
for connecting the speakers directly to the machine
A panel LOCK button to prevent tampering with the front panel
Previous setup recall via the non-volatile memory after power up
Changing the audio output levels via RS-232
The VP-23N can be controlled using the front panel buttons, or remotely via:
RS-485 or RS-232 serial commands transmitted by a touch screen
system, PC, or other serial controller
The Kramer Infra-Red remote control transmitter
The ETHERNET
3.3 Recommendations for Achieving the Best Performance
To achieve the best performance:
Connect only good quality connection cables, thus avoiding
interference, deterioration in signal quality due to poor matching,
and elevated noise- levels (often associated with low quality
cables)
Avoid interference from neighboring electrical appliances and
position your Kramer VP-23N away from moisture, excessive
sunlight and dust

Your Presentation Switcher
5
3.4 Terminology Used in this User Manual
Table 1 defines some terms that are used in this user manual.
Table 1: Terminology Used in this User Manual
Term Definition
802.3 The standard specification for ETHERNET that is maintained by the Institute of Electrical
and Electronics Engineers (IEEE).
Dynamic Host
Configuration
Protocol (DHCP)
Allows the network administrator to distribute IP addresses from a central point and
automatically send a new IP address when an Ethernet point is plugged into a different
network location
Gateway A network position serving as an entry to another network. On the Internet, a node or
stopping point can be either a gateway node or a host (end-point) node.
IP Address A 32-binary digit number that identifies each sender or receiver (within a network via a
particular server or workstation) of data (HTML pages or e-mails) that is sent in packets
across the Internet. Every device connected to an IP network must have a unique IP
address. This address is used to reference the specific unit.
Local Area Network
(LAN) Computers sharing a common communications line or wireless link, which often share a server within a defined geographic area.
Media Access
Control (MAC)
Address
A computer's unique hardware number (or address) in a LAN or other network. On an
Ethernet LAN, the (MAC) address is identical to the Ethernet address.
Transmission
Control
Protocol/Internet
Protocol (TCP/IP)
The basic communication language or protocol of the Internet that breaks the message
into appropriately sized packets for the network, and can be used as a communications
protocol in an intranet or an extranet.
4 Your Presentation Switcher
Figure 1, Figure 2, Table 2, and Table 3 describe the front and rear panels of
the VP-23N, respectively.

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Your Presentation Switcher
6
Figure 1: VP-23N Presentation Switcher – Front View

Your Presentation Switcher
7
Table 2: Front Panel VP-23N Presentation Switcher Features
# Feature Function
1 IR (Infra-Red) Receiver Signals from the remote control transmitter illuminate the
LED
2 POWER Switch Illuminated switch supplying power to the unit
3 VIDEO (CV)-AUDIO SELECTOR
Buttons Selects the composite video-audio source (from 1 to 4)
4 s-VIDEO (Y/C)-AUDIO SELECTOR
Buttons Selects the s-Video-audio source (from 1 to 4)
5 VGA/UXGA-AUDIO SELECTOR
Buttons Selects the VGA/UXGA video-audio source from (1 to 4)
6 CV Button Press to route the selected audio signal from the composite
video section to the master audio outputs
1
s-VIDEO Button Press to route the selected audio signal from the s-Video
section to the master audio outputs
1
VGA/UXGA Button
Press to route the selected audio signal from the
VGA/UXGA section to the master audio outputs
1
MASTER
AUDIO
SELECTOR
MIC Button Press to route the microphone input to the master audio
outputs
1
7 + Button
Increase the microphone audio signal level
8 MIC - Button Decrease the microphone audio signal level
9 + Button
Increase the master audio signal level
10
AUDIO LEVEL
MASTER
- Button Decrease the master audio signal level
11 TALK OVER Button Push the button to activate talk over
2
12 LOCK Button Press to lock the front panel buttons
1 MASTER OUT and SPKR OUT
2 With the TALK OVER button pressed in, speaking into the microphone amplifies the voice of the speaker, overriding and
fading out all other audio channels. However, pressing the MIC button in the Master Audio Selector renders the Talk Over
function inactive

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Your Presentation Switcher
8
Figure 2: VP-23N Presentation Switcher – Rear View

Your Presentation Switcher
9
Table 3: Rear Panel VP-23N Presentation Switcher Features
# Feature Function
1 MIC IN Connector Connect to the microphone
2 COND. / DYN Selector Switch
Push in to select a condenser, push out to select a dynamic
microphone
3 CV OUT
Terminal Block Connector Connect to the composite video balanced audio acceptor
4 Y/C OUT
Terminal Block Connector Connect to the s-Video balanced audio acceptor
5 UXGA OUT
Terminal Block Connector Connect to the VGA/UXGA balanced audio acceptor
6 MASTER OUT
Terminal Block Connector Connect the master balanced audio channel acceptor
1
7 CV IN
Terminal Block Connectors Connect to the composite video balanced audio sources
2
8 SPKR OUT
Terminal Block Connector Connect to a pair of loudspeakers
9 Y/C IN
Terminal Block Connectors Connect to the s-Video balanced audio sources
2
10
AUDIO
UXGA IN
Terminal Block Connectors Connect to the VGA/UXGA balanced audio sources
2
11 REMOTE IR 3.5mm Mini Jack Connect to an external IR receiver unit for controlling the machine
via an IR remote controller (instead of using the front panel IR
receiver)
3
12 CV IN BNC Connectors Connect to the composite video sources
2
13 CV OUT BNC Connector Connect to the composite video acceptor
14 Y/C IN 4p Connectors Connect to the s-Video sources
2
15 Y/C OUT 4p Connector Connect to the s-Video acceptor
16 UXGA IN HD15 Connectors Connect to the VGA/UXGA video sources
2
17
VIDEO
UXGA OUT HD15 Connector Connect to the VGA/UXGA video acceptor
18 ETHERNET Connector Connects to the PC or other Serial Controller through computer
networking
19 RS-232 DB 9F Port Connects to the PC or the Remote Controller
20 FLASH PROG. Button Push in for “Program” to upgrade to the latest Kramer firmware
(see section 8), or release for Normal (the factory default)
4
21 RS-485 Terminal Block Port Pins B (-) and A (+) are for RS-485; Pin G may be connected to
the shield (if required)
22 Dipswitches Dipswitches for setup of the unit (DIPs 1, 2 and 3 are for
setting the machine # and DIP 4 is for RS-485 termination;
see section 6.8)
1 Both the MASTER OUT and the SPKR OUT terminal block connecters receive the same signal: the MASTER OUT
outputs it as it is while the SPKR OUT is amplified
2 From 1 to 4
3 Optional. Can be used instead of the front panel (built-in) IR receiver to remotely control the VP-23N (only if the internal
IR connection cable has been installed)
4 The FLASH PROG reset button is located on the underside of the unit (see Figure 3)

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Your Presentation Switcher
10
# Feature Function
23 UXGA CAT 5 OUT
Twisted Pair Connector
Connect to a remote computer graphics acceptor via a
receiver (for example, the TP-120
1
)
24 Power Connector with Fuse AC connector enabling power supply to the unit
Figure 3 and Table 4 define the RESET button (located on the machine’s
underside).
RESET
Figure 3: VP-23N Presentation Switcher– Underside View
Table 4: VP-23N Underside Panel Feature
Feature Function
RESET Button Press to reset the unit prior to firmware upgrade (see section 8.3)
1 See section 6.1

Installing the VP-23N in a Rack
11
5 Installing the VP-23N in a Rack
This section describes how to install the VP-23N in a rack.
Before Installing in a rack How to Rack Mount
Before installing in a rack, be sure that the environment is
within the recommended range:
Operating temperature range +5ºto +45ºC (41ºto 113ºF)
Operating humidity range 10 to 90% RHL, non-condensing
Storage temperature range -20ºto +70ºC (-4ºto 158ºF)
Storage humidity range 5 to 95% RHL, non-condensing

CAUTION!!
When installing on a 19" rack, avoid hazards by taking
care that:
1. It is located within the recommended environmental
conditions, as the operating ambient temperature of a
closed or multi unit rack assembly may exceed the
room ambient temperature.
2. Once rack mounted, enough air will still flow around
the machine.
3. The machine is placed straight in the correct
horizontal position.
4. You do not overload the circuit(s). When connecting
the machine to the supply circuit, overloading the
circuits might have a detrimental effect on overcurrent
protection and supply wiring. Refer to the appropriate
nameplate ratings for information. For example, for
fuse replacement, see the value printed on the
product label.
5. The machine is earthed (grounded) in a reliable way
and is connected only to an electricity socket with
grounding. Pay particular attention to situations where
electricity is supplied indirectly (when the power cord
is not plugged directly into the socket in the wall), for
example, when using an extension cable or a power
strip, and that you use only the power cord that is
supplied with the machine.
To rack-mount a machine:
1. Attach both ear brackets to the
machine. To do so, remove the
screws from each side of the
machine (3 on each side), and
replace those screws through the
ear brackets.
2. Place the ears of the machine
against the rack rails, and insert the
proper screws (not provided)
through each of the four holes in the
rack ears.
Note that:
In some models, the front panel
may feature built-in rack ears
Detachable rack ears can be
removed for desktop use
Always mount the machine in the
rack before you attach any cables
or connect the machine to the
power
If you are using a Kramer rack
adapter kit (for a machine that is not
19"), see the Rack Adapters user
manual for installation instructions
(you can download it at:
http://www.kramerelectronics.com)

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Connecting the VP-23N Presentation Switcher
12
6 Connecting the VP-23N Presentation Switcher
This section describes how to:
Connect the rear panel (see section 6.1)
Wire the CAT 5 connector (see section 6.2)
Connect balanced or unbalanced stereo audio (see section 6.3)
Connect a PC or other controller via the RS-232 port (see section 6.4)
Connect a controller via the RS-485 port (see section 6.5)
Control the VP-23N via the ETHERNET (see section 6.6)
Cascade several machines (see section 6.7)
Set the dipswitches (see section 6.8)
6.1 Connecting the VP-23N Rear Panel
In Figure 4, the audio connections are not shown, except for the microphone
and speakers connections.
In this example, all the outputs are connected to the same projector. Use the
projector controller to switch between the VP-23N video outputs
1
.
To connect
2
the VP-23N, as illustrated in Figure 4, do the following
3
:
1. Connect the following video sources:
One
4
composite video source (for example, a
composite video player) to the CV IN 1 BNC
connector
One
4
s-Video source (for example, an s-Video player)
to the Y/C IN 1 4p connector
One
4
VGA/UXGA source (for example, a computer
graphics source) to the UXGA IN 1 HD15F connector
1 Or projector inputs
2 You do not need to connect all the inputs
3 Switch OFF the power on each device before connecting it to your VP-23N. After connecting your VP-23N, switch on its
power and then switch on the power on each device. Switching on the VP-23N, recalls the previous setup from the non-
volatile memory
4 Although in this example only one source is connected, you can connect all of the four inputs, that is, 12 in total

Connecting the VP-23N Presentation Switcher
13
2. Connect the acceptors to a projector
1
as follows:
The composite video CV OUT BNC connector to the
composite video input of the projector
The s-Video Y/C OUT 4p connector to the s-Video
input of the projector
The VGA/UXGA UXGA OUT HD15F connector to
the VGA/UXGA input of the projector
3. Connect the appropriate balanced audio sources and acceptors (not shown in
Figure 4).
4. Connect the MASTER OUT terminal block connector, if required (not
shown in Figure 4; see section 7.3).
5. Connect the SPKR OUT block connector to a pair of loudspeakers, by
connecting the left loudspeaker to the “L+” and the “L-” terminal block
connectors, and the right loudspeaker to the “R+” and the “R-” terminal
block connectors. Do not ground the loudspeakers.
6. Connect the UXGA CAT 5 OUT twisted pair connector (see section 6.2) to
a line receiver (for example, the TP-120 XGA Line Receiver
2
, which is
connected to a remote display).
7. Connect a dynamic or a condenser microphone
3
, if required, to the MIC IN
XLR connector.
8. As an option, you can connect a PC and/or controller to:
The RS-232 port (see section 6.4)
The RS-485 port (see section 6.5)
The ETHERNET (see section 6.6)
9. Connect the unit to additional machines (if required) via the RS-485 port
(see section 6.7).
10. Connect the power cord.
1 In this example a projector is used, but you can also connect separate outputs such as displays, video recorders and so on
2 The receiver receives the CAT 5 signal, decodes it and outputs it to a VGA acceptor
3 Use the Con / Dyn switch (refer to the rear panel, item 2 in Figure 2) to select a dynamic microphone or a condenser

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Connecting the VP-23N Presentation Switcher
14
Figure 4: Connecting the VP-23N Presentation Switcher

Connecting the VP-23N Presentation Switcher
15
6.2 Wiring the CAT 5 LINE OUT RJ-45 Connector
Table 5 and Figure 5 define the CAT 5 PINOUT, using a straight pin-to-pin
cable with RJ-45 connectors:
Table 5: CAT 5 PINOUT
EIA /TIA 568A EIA /TIA 568B
PIN Wire Color PIN Wire Color
1 Green / White 1 Orange / White
2 Green 2 Orange
3 Orange / White 3 Green / White
4 Blue 4 Blue
5 Blue / White 5 Blue / White
6 Orange 6 Green
7 Brown / White 7 Brown / White
8 Brown 8 Brown
Pair 1 4 and 5 Pair 1 4 and 5
Pair 2 3 and 6 Pair 2 1 and 2
Pair 3 1 and 2 Pair 3 3 and 6
Pair 4 7 and 8 Pair 4 7 and 8
Figure 5: CAT 5 PINOUT

KRAMER: SIMPLE CREATIVE TECHNOLOGY
Connecting the VP-23N Presentation Switcher
16
6.3 Connecting the Balanced/Unbalanced Stereo Audio
Input/Output
Figure 6, Figure 7, and Figure 8 illustrate how to wire a
balanced/unbalanced input and/or output connection:
L+
L-
G
R+
R-
Figure 6: Connecting a Balanced Stereo Audio Input/Output
L+
L-
G
R+
R-
Figure 7: Connecting an Unbalanced Stereo Audio Input
L+
L-
G
R+
R-
Figure 8: Connecting an Unbalanced Stereo Audio Output

Connecting the VP-23N Presentation Switcher
17
6.4 Connecting a PC
You can connect a PC (or other controller) to the VP-23N via the RS-232
port.
To connect using the Null-modem adapter provided with the machine
(recommended method):
Connect the RS-232 DB9 rear panel port on the VP-23N to the
Null-modem adapter and connect the Null-modem adapter with a
9-wire flat cable to the RS-232 DB9 port on your PC
To connect without using a Null-modem adapter:
Connect the RS-232 DB9 port on your PC to the RS-232 DB9 rear
panel port on the VP-23N, as Figure 9 illustrates
Female DB9 (From PC)
PIN 4 Connected to PIN 6
PINS 8, 7, 1 Connected together
If a Shielded cable is used, connect the shield to PIN 5
PIN 5 Connected to PIN 5 (Ground)
PIN 3 Connected to PIN 2
PIN 2 Connected to PIN 3
Male DB9
Figure 9: Connecting a PC without using a Null-modem Adapter
6.5 Connecting via RS-485
You can control a VP-23N unit via an RS-485 controller, or a Master
Programmable Remote Control system such as the Kramer RC-3000
1
.
To connect an RC-3000 to a VP-23N unit (see Figure 10), connect the RS-
485 terminal block port on the RC-3000 to the RS-485 port on the VP-23N
unit, as follows:
Connect the “A” (+) PIN on the RS-485 rear panel port of the
RC-3000 to the “A” (+) PIN on the RS-485 rear panel port of the
VP-23N unit
Connect the “B” (-) PIN on the RS-485 rear panel port of the
RC-3000 to the “B” (-) PIN on the RS-485 rear panel port of the
VP-23N unit
1 Previously known as the VS-3000