PairGain PG-Flex FLC-704 User manual

PG-FLEX 8 CHANNEL
CENTRAL OFFICE TERMINAL
LOOP START/GROUND START POTS UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
™363-704-104-01,¨
SECTION 363-704-104-01
Model List Number Part Number
FLC-704 4 150-1304-04

363-704-104-01, Revision 01
ii June 22, 1998 FLC-704 List 4
Revision History of This Practice
©Copyright 1998 PairGain Technologies, Inc.
PairGain is a registered trademark, and PG-Flex is a trademark of PairGain Technologies, Inc.
Information contained in this document is company private to PairGain Technologies, Inc., and shallnot be modified, used, copied,
reproduced or disclosed in whole or in part without the written consent of PairGain.
Other product names mentioned in this practice are used for identification purposes only and may be trademarks or registered
trademarks of their respective companies.
Revision Release Date Revisions Made
01 June 22, 1998 Initial Release

363-704-104-01, Revision 01 Using This Technical Practice
FLC-704 List 4 June 22, 1998 iii
USING THIS TECHNICAL PRACTICE
Two types of messages, identified by icons, appear in the text.
Notes contain information about special circumstances.
Cautions indicate the possibility of equipment damage or the possibility of personal injury.

Table of Contents 363-704-104-01, Revision 01
iv June 22, 1998 FLC-704 List 4
TABLE OF CONTENTS
Product Overview_____________________________________________________________________ 1
Description and Features................................................................................................................... 1
Front Panel......................................................................................................................................... 2
Specifications .................................................................................................................................... 3
Operational Capabilities.................................................................................................................... 4
Circuit Operation............................................................................................................................... 4
Loop Start Operation........................................................................................................... 4
Ground Start Operation....................................................................................................... 6
CLASS Features..................................................................................................................7
Forward Disconnect............................................................................................................ 7
Installation and Test___________________________________________________________________ 8
Unpacking.......................................................................................................................................... 8
Installing............................................................................................................................................ 8
Provisioning....................................................................................................................................... 8
Verify Installation.............................................................................................................................. 9
Troubleshooting............................................................................................................................... 10
Product Support _____________________________________________________________________ 11
Technical Support............................................................................................................................ 11
Warranty.......................................................................................................................................... 11
FCC Compliance............................................................................................................................. 12
Modifications................................................................................................................................... 12
Abbreviations _______________________________________________________________________ 13

363-704-104-01, Revision 01 Product Overview
FLC-704 List 4 June 22, 1998 1
PRODUCT OVERVIEW
This section provides a product description, and defines the features and specifications for the PairGain®
PG-Flex™ FLC-704 List 4 Central Office Terminal (COT) Channel Unit.
Description and Features
The FLC-704 List 4 channel unit provides eight loop start or ground start channel interfaces for Plain Old
Telephone Service (POTS) between a PG-Flex COT and the Central Office (CO) switch using A-Law pulse code
modulation (PCM) encoding. In addition, the FLC-704 List 4 provides metallic access to the subscriber line
connection through an optional metallic bypass pair for subscriber circuit testing.
Features of the PG-Flex FLC-704 List 4 COT channel unit are:
•eight loop start or ground start POTS subscriber interfaces
•64 kbps A-Law PCM encoding
•meter tones (12 kHz, 16 kHz)
•front panel ACTIVE LEDs indicate on-hook (idle), ringing, metallic access, and off-hook condition for each
channel
•front panel FAULT LED indicator simplifies troubleshooting
•Pair Gain Test Controller (PGTC) compatibility
•Custom Local Area Signaling Services (CLASS) support (such as, caller ID)
•line-side answer supervision support (reverse battery)
•forward disconnect
•distinctive ringing
•metallic access for subscriber circuit testing
•repeat of loop off-hook, ground start seizure, and Ring-Trip conditions to the CO switch

Product Overview 363-704-104-01, Revision 01
2 June 22, 1998 FLC-704 List 4
Front Panel
The FLC-704 List 4 front panel (Figure 1) includes green status LEDs for each line indicating on-hook (idle),
ringing, and off-hook conditions, as well as a red LED indicating a fault condition on the channel unit. Table 1
lists the different states and indications for the FLC-704 channel unit front panel LEDs.
Figure 1. FLC-704 List 4 Front Panel
Table 1. FLC-704 List 4 Front Panel LEDs and Labels
LED and Label Function
Solid green: Channel is off-hook.
ACTIVE
(1 through 8)
Fast flashing green: Channel is in test access mode.
Slow flashing green: LED follows the ring signal.
Off: Channel is on-hook (idle).
FAULT Red: Fault detected by the unit. Refer to Table 10 on page 10 for troubleshooting procedures.
Off: No faults detected.
Warranty Control
Number Label
Indicates the beginning year and month of the equipment warranty. Also indicates the unit
revision number. For example, a warranty control number of “71203” indicates a warranty
beginning 1997 (7), in December (12), and the revision is “03.”
Bar Code Label Contains the serial number and part number of the equipment in both bar code and text formats.
PairGain
FLC 704
CHAN UNIT
LIST
FAULT
4
A
C
T
I
V
E
1
2
3
4
5
6
7
8
Status LEDs
Fault LED
Warranty control
number label
Bar code label

363-704-104-01, Revision 01 Product Overview
FLC-704 List 4 June 22, 1998 3
Specifications
Electrical Characteristics
Analog Impedance 600 Ω
Loop Resistance 100 Ω, (CO switch to COT) maximum
End-to-End Loss –2.5 dB ±1.0 dB at 100 Hz
Ring-Ground Resistance 500 Ω
Channel Signature Loop Start Lines Ground Start Lines
Tip-Ring (open) 23.75k Ω, 1%
Tip-Ground 162k Ω, 1% 162k Ω, 1%
Ring-Ground 226k Ω, 1% 226k Ω, 1%
Environmental
Operating Elevation –200 ft. to 13,000 ft. (–60 m to 4000 m)
Temperature and Humidity –40° F to +150° F (–40° C to +65° C)
5% to 95% (non condensing)
Physical
Weight 0.8 lb (0.4 kg)
Dimensions
Height 6.75 in. (17.2 cm)
Width 1.00 in. (2.5 cm)
Depth 10.50 in. (26.7 cm)

Product Overview 363-704-104-01, Revision 01
4 June 22, 1998 FLC-704 List 4
Operational Capabilities
The FLC-704 List 4 channel unit provides eight loop start or ground start POTS interfaces to the CO switch. The
unit performs the interface function between the analog POTS circuit and the internal digital pulse coded
modulation (PCM) bus. In addition, each channel unit:
•detects forward battery
•detects ringing voltage
•detects reverse battery
•detects Tip ground and Tip open
•detects 12 kHz or 16 kHz meter tone
•detects a subscriber test access signal
•provides loop closure
•provides grounded ring lead
•converts analog signals to and from 64 kbps A-Law PCM digital format
Circuit Operation
The following paragraphs define the FLC-704 circuit operation when using loop start for subscriber lines or
ground start for PBX lines. Each FLC-704 circuit has an associated LED that indicates when the line is off-hook,
on-hook (idle), ringing, or under test (see Table 1 on page 2 for front panel LED definitions).
Loop Start Operation
The following section summarizes the loop start sequences for on-hook (idle), subscriber inititated outgoing calls,
subscriber received incoming calls, and busy conditions.
On-hook (Idle) Condition. Loop start idle condition is a Ring-lead negative and Tip-lead positive from the CO
with the same condition out of the RT toward the subscriber (see Table 2 for circuit interactions).
Subscriber Initiated Outgoing Call. The following occurs when the calling line goes off-hook (see Table 3
on page 5 for circuit interactions):
•loop current flows and is detected by the FLC-704 List 4 channel unit
•FLC-704 receives an off-hook signal from the RT
•FLC-704 generates an off-hook condition to the CO switch
•CO sends dial tone
•FRC-754 passes a dial pulse or Dual Tone Multi Frequency (DTMF) signal through the FLC-704 from the
subscriber and forwards these to the CO
Table 2. Circuit Interactions for an Idle Condition (Loop Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
Circuit Idle No ringing ⇒No ringing ⇒
⇐On-hook ⇐On-hook

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FLC-704 List 4 June 22, 1998 5
Subscriber Receives Incoming Call. The following occurs for an incoming call (see Table 4 for circuit
interactions):
•FLC-704 detects a ringing signal from the CO
•FLC-704 signals the FRC-754 which then connects ringing to the subscriber
•subscriber line goes off-hook and the FRC-754, through the FLC-704, provides an off-hook condition to the
CO switch
Busy Condition. Loop start busy condition at the RT is a Ring lead negative and a Tip lead positive with loop
current flowing. The same conditions occurs at the CO (see Table 5 for circuit interactions).
Table 3. Circuit Interactions When a Subscriber Initiates an Outgoing Call (Loop Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
CO Idle No ringing ⇒No ringing ⇒
Subscriber goes
off-hook ⇐Off-hook ⇐Off-hook
CO returns dialtone Dialtone ⇒Dialtone ⇒
Subscriber Dials ⇐DP or DTMF ⇐DP or DTMF
Table 4. Circuit Interactions When a Subscriber Receives an Incoming Call (Loop Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
Subscriber Idle ⇐On-hook ⇐On-hook
CO generates ringing Ringing ⇒Ringing ⇒
Subscriber goes
off-hook ⇐Off-hook ⇐Off-hook
Ring trip No ringing ⇒No ringing ⇒
Table 5. Circuit Interactions for a Busy Condition (Loop Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
Circuit busy No ringing ⇒No ringing ⇒
⇐Off-hook ⇐Off-hook

Product Overview 363-704-104-01, Revision 01
6 June 22, 1998 FLC-704 List 4
Ground Start Operation
The following section summarizes the ground start sequences for on-hook (idle), subscriber inititated outgoing
calls, subscriber received incoming calls, and busy conditions.
Idle Condition. Ground start idle condition is a Tip-lead open and Ring-lead negative from the CO andTip lead
open and Ring-lead negative at the RT (see Table 6 for circuit interactions).
Subscriber Initiates Outgoing Call. The following occurs when a PBX requests service for an outgoing call
(see Table 7 for circuit interactions):
•PBX grounds Ring lead at the RT
•FRC-754 signals the FLC-704
•FLC-704 operates a Ring-ground relay that requests dial tone from the CO (this makes the circuit busy, or
seizes it, for outgoing calls, and blocks any incoming calls prior to the PBX dialing (that is, it prevents glare
where incomingand outgoing calls may occursimultaneously on the same line). Glare occurswhen both ends
of a telephone line or trunk are seized at the same time.
•CO sends dial tone and grounds the Tip to signal the PBX to begin dialing
•FLC-704 detects Tip-ground, closes the loop between Tip and Ring, and signals the FRC-754 to send Tip
ground to the PBX
•PBX removes the original Ring-ground condition and completes the loop (Tip and Ring)
Table 6. Circuit Interactions for an Idle Condition (Ground Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
Circuit Idle Tip - no ground
No ringing ⇒Tip - no ground No ringing ⇒
⇐Ring - no ground
On-hook ⇐Ring - no ground On-hook
Table 7. Circuit Conditions When a Subscriber Initiates an Outgoing Call (Ground Start)
Operation CO Switch FLC-704 List 4 COCU FRL-754 List 4 RTCU Subscriber
CO Idle Tip - No ground
No ringing ⇒Tip - No ground No ringing ⇒
Subscriber requests
dialtone ⇐Ring - ground On-hook ⇐Ring - ground On-hook
CO returns dialtone Tip - ground
Dialtone ⇒Tip - ground Dialtone ⇒
Subscriber Dials ⇐Ring - no ground
Off-hook
DP or DTMF
⇐Ring - no ground
Off-hook
DP or DTMF