Comrex STAC User manual

STAC (STUDIO TELEPHONE ACCESS CENTER)
TABLE OF CONTENTS
SECTION 1
SECTION 2
SECTION 3
SECTION 4
SECTION 5
...........INTRODUCTION......................................................................................... 7
.......................STAC FEATURES .......................................................................... 7
.......................WHAT COMES WITH STAC ............................................................ 7
...........MAINFRAME DIAGRAMS AND INSTALLATION ...................................................... 8
.......................REAR PANEL DIAGRAM AND DESCRIPTIONS .......................................... 8
.......................PHONE LINE CONNECTIONS ............................................................ 9
.......................PHONE LINE PINOUTS ................................................................... 10
.......................XLR PINOUTS ............................................................................. 10
.......................FRONT PANEL DIAGRAM AND DESCRIPTIONS ........................................ 11
.......................DIP SWITCHES ............................................................................ 12
.......................STAC MAINFRAME STATUS INDICATIONS............................................. 14
...........CONTROL SURFACE DIAGRAMS AND INSTALLATION ............................................. 15
.......................BASICS....................................................................................... 15
.......................TOP VIEW DIAGRAM AND DESCRIPTIONS ............................................. 16
.......................REAR VIEW DIAGRAM AND DESCRIPTIONS ........................................... 17
.......................SIDE VIEW DIAGRAM AND DESCRIPTIONS ............................................ 17
.......................CONFIGURATION........................................................................... 18
.......................DIP SWITCH SETTINGS .................................................................. 18
.......................MORE ABOUT THE AUX/NEXT BUTTON AND CONTACT CLOSURES ............. 19
...........CONTROL SURFACE OPERATION.................................................................... 21
.......................SCREENER CONTROL SURFACE .......................................................... 21
.......................TYPICAL SCREENER OPERATION ........................................................ 21
.......................STUDIO CONTROL SURFACE ............................................................ 22
.......................TYPICAL STUDIO OPERATION ........................................................... 22
.......................OTHER CONTROL SURFACE INDICATIONS ............................................ 23
...........STAC IP ............................................................................................... 25
.......................ABOUT STAC IP ......................................................................... 25
.......................SETUP........................................................................................ 25
.......................REQUIREMENTS ............................................................................ 25
.......................IP ADDRESS CONFIGURATION .......................................................... 25
.......................STATIC VS. DYNAMIC ADDRESSING..................................................... 26
.......................DYNAMIC CONFIGURATION .............................................................. 26
.......................STATIC CONFIGURATION ................................................................. 26
.......................GAINING ACCESS .......................................................................... 27
.......................STAC IP INTERFACE ..................................................................... 27
.......................STAC IP SCREEN......................................................................... 28
.......................MAJOR STAC IP FUNCTIONS .......................................................... 28
.......................BUTTON STATUS ........................................................................... 30
.......................USING STAC IP WITHOUT A MOUSE ................................................ 31
.......................INDIVIDUAL LINE COMMANDS .......................................................... 31

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...........STAC IP (CONTINUED)
.......................GLOBAL COMMANDS ..................................................................... 31
.......................ESCAPING COMMAND MODE PREMATURELY ......................................... 32
.......................OTHER FUNCTIONS ....................................................................... 32
.......................ASSOCIATING STAC IP WITH A CONTROL SURFACE .............................. 32
.......................CHANGING THE STAC IP PASSWORD ................................................ 33
.......................TROUBLESHOOTING REMOTE STAC IP............................................... 33
.......................DELIVERING STAC IP OUTSIDE THE LAN ENVIRONMENT....................... 34
...........STAC HYBRID SETUP AND OPERATION .......................................................... 35
.......................STAC BLOCK DIAGRAM................................................................. 35
.......................ABOUT HYBRIDS IN GENERAL .......................................................... 36
.......................ABOUT THE STAC HYBRIDS............................................................ 36
.......................TELEPHONE SEPARATION/NULL ......................................................... 37
.......................AUTOMATIC GAIN CONTROL ............................................................ 37
.......................AUTOMATIC MIX-MINUS................................................................. 37
.......................CALLER CONTROL ......................................................................... 37
.......................ABOUT MIX-MINUS....................................................................... 38
.......................BUILDING A MIX-MINUS ................................................................ 38
.......................TRIM POTS.................................................................................. 45
...........CONFORMITY AND REGULATORY INFORMATION ................................................. 47
...........TABLE 1 - PHONE LINE PINOUT ................................................................... 10
...........TABLE 2 - XLR PINOUT ............................................................................. 10
...........TABLE 3 - PARALLEL PORT PINOUT ................................................................ 14
...........TABLE 4 - CONTACT CLOSURE AND AUX/NEXT DIP SWITCH SETTINGS ................... 20
...........TABLE 5 - SCREENER STATES/INDICATIONS ....................................................... 21
...........TABLE 6 - STUDIO STATES/INDICATIONS .......................................................... 22
...........TABLE 7 - STAC IP STATES/INDICATIONS ....................................................... 30
...........TABLE 8 - CONTROL SURFACE ASSIGNMENT MENU ............................................ 32
...........FIGURE 1 - STAC HYBRID CONFERENCING..................................................... 38
...........FIGURE 2A - CONSOLE PROVIDES MIX-MINUS BUS........................................... 39
...........FIGURE 2B - USING AUDITION BUS ON CONSOLE............................................. 40
...........FIGURE 3 - USING MIX-MINUS MODULE ........................................................ 41
...........FIGURE 4 - CONNECTING EXTERNAL HYBRID ................................................... 42
...........FIGURE 5 - FEEDING MIC AUDIO ONLY ......................................................... 43
...........FIGURE 6 - USING AUTO MIX-MINUS ............................................................ 44
SECTION 6
APPENDIX A
TABLE LISTING
FIGURE LISTING

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About Comrex
Comrex has been building reliable, high quality broadcast equipment since 1961.
Our products are used daily in every part of the world by networks, stations and
program producers.
Every product we manufacture has been carefully designed to function flawlessly,
under the harshest conditions, over many years of use. Each unit we ship has been
individually and thoroughly tested. Most items are available off the shelf, either
directly from Comrex or from our stocking dealers.
Comrex stands behind its products. We promise that if you call us for technical as-
sistance, you will talk directly with someone who knows about the equipment and
will do everything possible to help you.
Our toll free number in North America is 800-237-1776. Product information
along with engineering notes and user reports are available on our website at
http://www.comrex.com. Our email address is [email protected].
Warranty and Disclaimer
All equipment manufactured by Comrex Corporation is warranted by Comrex
against defects in material and workmanship for one year from the date of original
purchase, as verified by the return of the Warranty Registration Card. During the
warranty period, we will repair or, at our option, replace at no charge a prod-
uct that proves to be defective, provided you obtain return authorization from
Comrex and return the product, shipping prepaid, to Comrex Corporation, 19
Pine Road, Devens, MA 01434 USA. For return authorization, contact Comrex at
978-784-1776 or fax [phone].
This Warranty does not apply if the product has been damaged by accident or
misuse or as the result of service or modification performed by anyone other than
Comrex Corporation.
With the exception of the warranties set forth above, Comrex Corporation makes
no other warranties, expressed or implied or statutory, including but not limited
to warranties of merchantability and fitness for a particular purpose, which are
hereby expressly disclaimed. In no event shall Comrex Corporation have any li-
ability for indirect, consequential or punitive damages resulting from the use of
this product.
Copyright Notice
The Comrex proprietary code and licensed, third party proprietary code residing
in and otherwise associated with this product are protected by copyright law and
international treaties. Unauthorized reproduction or distribution of this product,
or any portion of it, may result in civil and criminal sanctions, and will be pros-
ecuted to the fullest extent of the law.
US Government Restricted Rights - Use, duplication, or disclosure by the US Gov-
ernment is subject to restrictions set forth in subparagraph (c)(1)(ii) of the Rights
in Technical Data and Computer Software clause at DFARS (48 CFR) 252.227-7013
or subparagraphs (c)(1) and (2) of the Commercial Computer Software-Restricted
Rights clause at FAR (48 CFR) 52.227-19, as applicable.
STAC contains Macromedia® Flash™ technology by Macromedia, Inc. Copyright
©1995-2003 Macromedia, Inc. All rights reserved. Macromedia, Flash, Macrome-
dia Flash, and Macromedia Flash Lite are trademarks or registered trademarks of
Macromedia, Inc. in the United States and other countries.

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This document is the End User License Agreement for the Macromedia Flash Player
embedded into the STAC firmware. This player is required for implementation of
“Console STAC IP” as outlined in this manual on page 25.
If you cannot agree to the terms of this EULA, please notify Comrex and we will
provide firmware that removes this function.
END USER LICENSE AGREEMENT
(UNITED STATES OF AMERICA)
NOTICE TO ALL USERS: PLEASE READ THE FOLLOWING LEGAL AGREEMENT
(“AGREEMENT”) CAREFULLY, FOR THE LICENSE OF THE VERIFIED PORTED
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LICENSED BY AND THROUGH VIBREN TECHNOLOGIES, INC. (“LICENSOR”). BY
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YOUR COMPANY (“YOU”) CONSENT TO BE BOUND BY AND BECOME A PARTY
TO THIS AGREEMENT. IF YOU ARE AN EMPLOYEE OR AGENT OF A COMPANY
AND YOU ARE ORDERING ITEMS FOR USE BY SUCH COMPANY AND ITS EM-
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Use. The Player is licensed as a single product; it may not be used on more than
one (1) Device, except as set forth in this Section 1.
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lier terminated as set forth in this Agreement. Licensor may terminate this Agree-
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directly or indirectly, into any country in violation of any applicable law (including, but not
limited to, the United States Export Administration Act and the regulations promulgated
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SECTION 1 INTRODUCTION
Comrex STAC (Studio Telephone Access Center) is a multiline on-air
telephone system, available for six lines (STAC6) or twelve lines (STAC12).
Both versions offer the following features:
• Intuitive, attractive control surfaces with built-in handsets for
call screening.
• Mainframe containing two state-of-the-art digital telephone
hybrids for natural sounding caller audio.
• Control surfaces, up to four per system, configurable for
Screener or Studio functions.
• All telco and control surface connections via UTP cable and
RJ-45 connectors.
• Self-powered control surfaces.
• Telephone line Loop-Thru access.
• Auto-answer and auto-disconnect of phone lines.
• Auto Attendant answers lines and plays your pre-recorded
message to caller.
• STAC IP allows mainframe to be used as server for remote
control functions.
• STAC IP delivers web page for remote control.
The following items are shipped with a new STAC System:
(1) STAC mainframe with one or two six-line telco cards*
(1) STAC control surface (with sidecar for twelve-line operation)
(1) AC power cord for mainframe
(1) RJ-45 cable for control surface
(1) Operating manual
(1) Warranty card (Please fill out and return.)
*The STAC system is delivered as a six or twelve-line model. A six-line STAC
(STAC6) can be upgraded to a twelve-line STAC (STAC12) with one addi-
tional telco board and a sidecar for the control surface to allow line control
for six more lines.
STAC FEATURES
WHAT COMES WITH STAC

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SECTION 2 MAINFRAME DIAGRAMS AND INSTALLATION
REAR PANEL DIAGRAM AND DESCRIPTIONS
SEND IN HOLD AUDIO IN AUX OUT HYBRID 1 OUT HYBRID 2 OUT
EXPANSION
PORT
1
1 - 3
PHONE LINE IN
4 - 6 1 - 3
LOOP-THRU OUT
4 - 6
7 - 9 10 - 12 7 - 9 10 - 12
AC POWER IN
1
CONTROL SURFACE
23 4
123
4
5
67
8910 11 12
13
14
18 16
17
15
1) AC POWER SELECT SWITCH
2) AC INPUT
3) AC OUTPUT
4) MOUSE PORT
5) KEYBOARD PORT
6) VGA OUTPUT PORT
7) NETWORK ACCESS PORT
8) SEND IN CONNECTOR
9) ON HOLD CONNECTOR
10) AUX OUT CONNECTOR
This switch is used to select whether the unit will be powered by 115VAC
or 230VAC.
This is an IEC connector for the main power. STAC works on worldwide
AC power at 115VAC or 230VAC.
This is an IEC style power port for optional computer monitor.
This port is used for connecting a PS/2 style mouse (if desired).
This port is used for connecting a PS/2 style keyboard (if desired).
This VGA style port is used for connecting a computer monitor.
This RJ-45 jack provides an Ethernet connection to serve STAC IP.
This is a balanced female XLR connector designed to accept either line or
microphone level audio, selectable via DIP switch. (See the DIP SWITCH sec-
tion on page 12.) The audio present here will be sent to callers when they
are On Air.
This 3-pin female XLR connector is designed to accept balanced, line level
audio. This is the audio which callers will hear when placed On Hold.
This balanced 3-pin male XLR connector contains a mix of Hybrid 1 and
Hybrid 2 audio. Send audio may also be added to this output, selectable
via DIP switch. (See the DIP SWITCH section on page 12.)
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This is a 3-pin male XLR connector with balanced line level output contain-
ing the audio of the caller(s) on Hybrid 1.
This is a 3-pin male XLR connector with balanced line level output contain-
ing the audio of the caller(s) on Hybrid 2.
Use this RJ-45 jack to connect an external hybrid to STAC. Refer to page 42
for additional information.
These four RJ-45 jacks provide connection of telephone lines 1-6 and 7-12
to the mainframe. See the PHONE LINE PINOUTS section on page 10 for wiring
instructions.
These four RJ-45 jacks provide optional Loop-Thru connections for tele-
phone lines 1-6 and 7-12, allowing access to designated telephone lines
when STAC is not using them. STAC can also be configured via DIP switch-
es to disable line access when a Loop-Thru device is active on that line.
Refer to the DIP SWITCH section on page 12 for details.
Note: A STAC6 System only has phone line and loop-thru functions for lines
1-6.
Use these RJ-45 jacks to connect up to four control surfaces to the main-
frame with standard four-pair cable (Cat-4 or better).
This port provides status indications for Ringing and On Air lines. For details
see STAC MAINFRAME STATUS INDICATIONS on page 14.
Phone Line and Loop-Thru connections are made via RJ-45 cables,
pinned such that each phone line is on one twisted pair of a four-pair cable
(Cat-4 or better) as shown on page 10. Only three pairs are used on each
jack. (Pair 4 is unconnected.) The use of the Loop-Thru connections is
optional. If used, the Loop-Thru connections will provide access to each
designated telephone line when STAC is not using it. Also, STAC can be set
to disable line access when a Loop-Thru device is active on that line. (See
page 13 for more information.)
Comrex sells a “STAC Breakout Box Kit” that provides RJ-11 access to each
phone line and Loop-Thru port on STAC. One kit is required for access to
six telephone lines. If Loop-Thru access is required, two kits are required
for each group of six phone lines.
11) HYBRID 1 OUTPUT
CONNECTOR
12) HYBRID 2 OUTPUT
CONNECTOR
13) HYBRID EXPANSION
PORT
14) PHONE LINES 1-6
15) PHONE LINES 7-12
16) LOOP-THRU 1-6
17) LOOP-THRU 7-12
18) CONTROL SURFACE
JACKS
19) PARALLEL PORT
PHONE LINE CONNECTIONS

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XLR PINOUTS
Phone connections require one pair of wires for each line. They are typi-
cally designated Tip (or Red) and Ring (or Green). Table 1 shows the exact
pinout of the jacks. Note that pinout is identical on the Phone Line jacks
and the Loop-Thru Jacks.
Table 1 - Phone Line Pinout
RJ-45 Pin Number Line Number Tip/Ring
1 2/5/8/11 Tip
2 2/5/8/11 Ring
3 3/6/9/12 Tip
4 1/4/7/10 Tip
5 1/4/7/10 Ring
6 3/6/9/12 Ring
7 Unused
8 Unused
STAC audio connections are balanced professional level inputs and out-
puts. All XLRs are pinned as follows:
Table 2 - XLR Pinout
Pin 1 Ground
Pin 2 Audio +
Pin 3 Audio -
PHONE LINE PINOUTS

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FRONT PANEL DIAGRAM AND DESCRIPTIONS
INPUT HYBRID 1 HYBRID 2
12 3 4 5 6 7 8
1) INPUT INDICATOR
2) HYBRID 1 INDICATOR
3) HYBRID 2 INDICATOR
4) SEND LEVEL ADJUST
5) ON HOLD SEND AUDIO
ADJUST
6) AUX OUT RECEIVE AUDIO
ADJUST
7) HYBRID 1 OUT
ADJUSTMENT
8) HYBRID 2 OUT
ADJUSTMENT
This indicates the Send Input level, or the level of audio sent to callers
when On Air. This indicator should be green during typical audio. It will
light amber when the system is approaching its limit and red when the
system is clipping.
This indicates the incoming level of the call(s) on Hybrid 1. This indicator
should be green during typical audio. It will light amber when the system is
approaching its limit and red when the system is clipping.
This indicates the incoming level of the call(s) on Hybrid 2. This indicator
should be green during typical audio. It will light amber when the system is
approaching its limit and red when the system is clipping.
Use this control to adjust the audio level sent to the caller. The Input Indi-
cator (1) should be used to make this adjustment.
Use this control to adjust the audio sent to the callers when they are On
Hold. This adjustment should be made with program audio being sent into
the Hold Audio input. To make the adjustment, place a call into the system
(using an external telephone) and put the call On Hold. Adjust this level
for a good sounding signal on the telephone.
Use this control to match the Aux Out level to that of your console or re-
corder.
Use this control to match the Hybrid 1 Out level to match that of your
console or recorder. Note this adjusts level of the output stage only (i.e.
this does not boost the caller level into the hybrid).
Use this control to match the Hybrid 2 Out level to match that of your
console or recorder. Note this adjusts level of the output stage only (i.e.
this does not boost the caller level into the hybrid).

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DIP SWITCHES
1 - 8
9 - 16 (Note: The
UP position = ON )
ON = Microphone level send input (–70 to –50 dBu)
OFF = Line level send input (–10 to +10 dBu)
Note: This switch only affects the On Air Send Input. The Hold Audio
Input is always line level.
ON = Add 6 dB gain to the incoming phone lines. Useful in situations with
exceptionally low incoming phone line level.
ON = Add On Air Send audio to the Aux Out output.
OFF = Only Hybrid 1 and Hybrid 2 receive audio are present at the Aux
Out output.
ON = A short noise burst is sent down each line when it is put On Air. This
helps the hybrids to adapt more quickly but can be distracting to callers.
OFF = No noise burst is sent, but a short alert tone is sent to notify callers
they are On Air.
These switches control whether any caller suppression is applied. Caller
suppression allows the send audio input (for instance, a talk-show host)
to dynamically control the level of the incoming caller audio. This not
only enhances the perceived trans-hybrid loss of STAC but also allows the
studio host to control the conversation, since he or she can more easily
“talk over” the callers. When DIP Switch 5 is ON, 6 dB of caller control is
applied on the presence of host audio. When DIP Switch 6 is ON, 12 dB is
applied. When both DIP Switches 5 & 6 are ON, a very aggressive 18 dB
of caller suppression is applied.
ON = STAC will dynamically adjust the level of incoming caller audio to
provide more uniform level output on the incoming caller audio.
OFF = No AGC is applied to the incoming caller audio.
1) ON AIR SEND INPUT
LEVEL
2) CALLER BOOST
3) AUX MIX
4) BURST ADAPT
5 & 6) CALLER “DUCKING”
CONTROL
7) AGC

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See the AUTOMATIC MIX-MINUS section on page 37 for a description of this
function. Most applications should leave this switch set OFF.
ON = VIP/Hotline Mode enabled. In this mode, the system’s last two phone
lines (lines 5-6 on STAC6 or lines 11-12 on STAC12) are treated separately
for talk show guests or studio hotline functions. These lines are removed
from the Priority Queue, and Auto Attendant will not answer these lines.
OFF = All lines will participate in the Priority Queue and Auto Attendant
functions (if enabled).
ON = Auto Attendant will answer incoming calls on the sixth ring.
OFF = Auto Attendant will answer incoming calls on the second ring.
ON = Loop-Thru sensing is ignored.
OFF = Loop-Thru sensing is enabled. When enabled, this function disables
access to phone lines that have been picked up downstream of STAC.
“Downstream” devices are those connected via the telephone line Loop-
Thru ports on STAC. When this function is enabled, a downstream device
going off-hook will be indicated by a special light sequence on the control
surfaces, and those lines will be disabled on STAC until the downstream
device goes on-hook.
Note: When the STAC has taken a line “off hook”, it is always disabled at
the Loop-Thru jack.
ON = Lines must be dropped manually by control surfaces or STAC IP.
OFF = Lines will drop on sensing of momentary break in battery voltage
(calling party disconnect signal).
ON = Disable Auto Attendant regardless of control surface settings.
OFF = Control surfaces determine Auto Attendant function.
For future use.
8) AUTO MIX-MINUS
9) VIP/HOTLINE MODE
10) AUTO ATTENDANT 2/6
RINGS
11) LOOP THRU SENSE
DISABLE
12) AUTO DISCONNECT
DISABLE
13) AUTO ATTENDANT
GLOBAL DISABLE
14, 15 & 16) FUTURE

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The STAC mainframe provides status indications via the DB-25 parallel
port on the rear panel. This is essentially a computer printer port, so it is
only capable of sending TTL level status signals and cannot source or sink
significant current. An accessory box is available to convert these signals to
relay-based contact closures, capable of switching high voltages and cur-
rents directly.
The interface box we tested is model CK1621 available from Carl’s Elec-
tronics at http://www.electronickits.com - [phone]. This device
provides normally-open and normally-closed contacts for each of the eight
signals available on the parallel port.
Note: The CK1621 is not supplied with a 12V power supply or straight-
through DB-25 cable, both of which are available at electronic retailers
like Radio Shack.
At this time, two signals are available on the parallel port of the STAC main-
frame (using firmware 1.2 or higher):
Table 3 - Parallel Port Pinout
Pin # Name Description
2Line Ringing
(Active High) Goes Active when any line is Ringing
3Record Trigger
(Active High) Goes Active when any line is put On Air
Ground is available on Pins 18-25 of this connector.
STAC MAINFRAME STATUS
INDICATIONS

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STAC is delivered with one control surface. Four ports are present on the
STAC mainframe, so up to four control surfaces may be used. Additional
control surfaces are available from Comrex. Each control surface contains
one telephone handset, useful for screening or dialing calls. The control
surfaces require Cat-4 (or better) wiring with Ethernet style pinning, using
all four pair on the RJ-45 cable. Avoid underpinned and cross-over cables.
The control surfaces are powered over this cable and can be extended to
100 feet.
Before setting up a control surface for use with STAC, you must determine
whether the surface will be used as a Screener or a Studio surface. The ma-
jor differences are listed below:
1) Only Studio control surfaces can put calls On Air.
2) Only Studio control surfaces provide indication of which hybrid is
being used for each call.
3) Studio control surfaces share a single button for Answer and On
Hold.
4) Screener surfaces have separate buttons for Answer and On Hold.
5) Studio and Screener surfaces have different color lights to indicate
the various states of each phone line.
If you plan on using only one control surface (without STAC IP), you must
configure the surface for Studio, since this will be the only way to put calls
On Air. Studio surfaces can perform all functions of Screener surfaces.
SECTION 3 CONTROL SURFACE DIAGRAMS AND INSTALLATION
BASICS

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1) HANDSET
2) DIAL PAD
3) AUX/NEXT
4) BUSY ALL
5) CHANGE PRIORITY
6) AUTO ATTENDANT
7) ANSWER (ANSWER/HOLD)
8) HOLD (ON AIR)
9) DROP
10) LEGEND
Used to screen incoming calls and to make outgoing calls.
Used to send touch tone dialing to the phone line selected.
Depending on DIP switch settings, can be used to trigger an external de-
vice via contact closure (Aux function) or to select the next call to put On
Air (Next Function). Function selected via DIP switch. (See MORE ABOUT THE
AUX/NEXT BUTTON AND CONTACT CLOSURES section, page 19.)
Used to take all lines Off Hook before contests.
Used to change which line is currently set as the Priority line (Next to air).
Used to enable/disable the Auto Attendant function. (See page 23.)
These buttons are used to pick up lines and route them to the handset. In
Studio mode, this button is also used to put lines On Hold.
When configured as a Screener surface, this button puts the selected line
On Hold. When configured as a Studio surface, this button puts the select-
ed line On Air.
Hangs up selected line, whether it is on the handset, On Hold or On Air.
This label defines the button functions for the Studio and Screener modes.
1
2
3456
7
8
9
10
TOP VIEW DIAGRAM AND DESCRIPTIONS

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11
12 13
14 15
These switches determine the configuration of the STAC control surface.
See CONFIGURATION on page 18 for further details.
A contact closure (configurable via the control surface DIP Switches) is
available on Pins 7 & 8, useful for controlling a profanity delay or recorder.
This RJ-45 connector requires a UTP type cable to connect to one of the
four STAC mainframe control ports.
Used to adjust headset volume (does not affect handset volume).
Two 1/8” jacks for connection of a PC soundcard-compatible headset for
call screening.
11) DIP SWITCHES (6)
12) DB-9 CONNECTOR
13) CONNECTION TO
MAINFRAME
14) VOLUME ADJUSTMENT
15) HEADSET CONNECTORS
(MIC/HEADPHONE)
REAR VIEW DIAGRAM AND DESCRIPTIONS
SIDE VIEW DIAGRAM AND DESCRIPTIONS

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CONFIGURATION
DIP SWITCH SETTINGS
1) SCREENER/STUDIO
SURFACE
2 & 3) AUX/NEXT BUTTON
& CONTACT CLOSURES
4) FUTURE
5) HEADSET/HANDSET
MODE
6) HANDSET BOOST
The STAC control surface is configured via six DIP Switches on the rear
panel (shown as #11 of the REAR VIEW diagram on page 17). Each control
surface connected to STAC may be configured independently. The DIP
Switches are considered ON when they are in the UP position (i.e. the
actuator points toward the top of the surface).
The DIP Switches have the following functions:
ON = Screener surface.
OFF = Studio surface.
STAC control surfaces are provided with a removable and reversible legend
that shows the functions of the line buttons in each of the two available
modes. Make sure the legend follows the setting for DIP Switch 1.
Configure Aux/Next Button and DB-9 Contact Closure pins on control
surface.
Note: For a full description of the Next and Aux functions and Contact
Closures, see page 19.
For future use.
ON = Handset operates normally.
OFF = Headset plugged in to control surface. (Lines can be answered in
this mode without lifting the handset.)
ON = Handset audio level normal.
OFF = Handset audio increased by 6 dB (for hearing impaired).
Note: The default settings for a control surface (as shipped from the factory)
are DIP Switches 1,2,3 OFF and DIP Switches 5,6 ON.

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The Aux/Next button has several functions which are controlled by the
settings of DIP Switches 2 & 3 on the control surface. The configuration
of these DIP Switches also alters the Contact Closure function (available
on Pins 7 & 8 of the control surface DB-9 connector).
Essentially, the button can trigger the contact closure directly (Aux Mode)
either in momentary or latching fashion. Alternatively, the button can put
the priority line to air (Next Mode).
Note: You cannot manually control the contact closure while using the
Next Mode.
While in Next Mode, the contact closure on the control surface works
differently. It provides a status indication that can be configured to close
when any line is On Air (Record trigger) or when any line is Ringing (Line
Ringing Indicator).
Table 4 on page 20 shows the DIP Switch configuration for each mode.
DIP Switches are ON when they are up (actuator points to the top of the
control surface).
MORE ABOUT THE
AUX/NEXT BUTTON AND
CONTACT CLOSURES

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Table 4 - Contact Closure and Aux/Next DIP Switch Settings
Dip
Switch
2
Dip
Switch
3
Contact Closure and Aux/Next Function
On On
Latching Manual Closure
Defaults to Open. Toggles between Closed and Open
when Aux/Next button is pressed.
(Button has no effect on line status.)
On Off
Momentary Manual Closure
Closed when Aux/Next button is pressed.
Open when Aux/Next button is released.
(Button has no effect on line status.)
Off Off
Record Trigger
Closed when any lines On Air. Open when no lines
On Air.
Aux/Next button acts as Next function.
(Puts Priority line to On Air.)
Off On
Line Ringing Indication
Closed when any lines are ringing. Open when no
lines are ringing.
Aux/Next button acts as Next function.
(Puts Priority line to On Air.)
Note: The control surface contact closure is NOT rated for high voltages or
currents. DO NOT switch AC mains power using this closure.
Note: Record Trigger and Line Ringing Indication are also available from
the mainframe. See STAC MAINFRAME STATUS INDICATIONS on page 14 for details.