PairGain PG-Flex FRC-754 L4 User manual

PG-FLEX 8 CHANNEL REMOTE TERMINAL
LOOP START/GROUND START POTS UNIT
PAIRGAIN TECHNOLOGIES, INC.
ENGINEERING SERVICES TECHNICAL PRACTICE
™363-754-104-01J¨
SECTION 363-754-104-01
Model List Number Part Number
FRC-754 4 150-1354-04

363-754-104-01, Revision 01
ii June 22, 1998 FRC-754 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 PairGainTechnologies, 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

363-754-104-01, Revision 01 Using This Technical Practice
FRC-754 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 363-754-104-01, Revision 01
iv June 22, 1998 PG-Flex FRC-754 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 _______________________________________________________________________ 12

363-754-104-01, Revision 01 Product Overview
PG-Flex FRC-754 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™ FRC-754 List 4 Remote Terminal (RT) Channel Unit.
Description and Features
The FRC-754 List 4 channel unit provides eight loop start or ground start Plain Old Telephone Service (POTS)
interfaces between a PG-Flex RT andsubscribers. The FRC-754 List 4 uses A-Law pulse code modulation (PCM)
encoding. For subscriber circuit testing, the FRC-754 List 4 provides metallic access to the subscriber line
connection through an optional metallic bypass pair.
Features of the PG-Flex FRC-754 List 4 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
•application of ringing voltage
•detection of loop off-hook, ground start seizure, and Ring-Trip conditions

Product Overview 363-754-104-01, Revision 01
2 June 22, 1998 PG-Flex FRC-754 List 4
Front Panel
The FRC-754 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 FRC-754 List 4 front panel LED states and functions, and describes the labels.
Figure 1. FRC-754 List 4 Front Panel
Table 1. FRC-754 List 4 Front Panel LEDs and Labels
LED and Labels 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. See 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
1
A
C
T
I
V
E
2
3
4
5
6
7
8
FAULT
FRC 754
CHAN UNIT
LIST 4
Status LEDs
Fault LED
Warranty control
number label
Bar code label

363-754-104-01, Revision 01 Product Overview
PG-Flex FRC-754 List 4 June 22, 1998 3
Specifications
Electrical Characteristics
Analog Impedance 600 Ω
Subscriber Drop 960 Ω(including 430 Ωfor the handset)
DC Loop Current ≥23 mA
Ringer Output 40 V RMS, 3 lines simultaneously, 5 REN each
End-to-End Loss -2.5 dB ± 1.0 dB at 1004 Hz
Lightning Protection Meets all requirements (GR-CORE-1089, Section 4)
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 0.6 lb (0.3 kg)
Dimensions
Height 12.00 in. (30.5 cm)
Width 1.00 in. (2.5 cm)
Depth 4.50 in. (11.4 cm)

Product Overview 363-754-104-01, Revision 01
4 June 22, 1998 PG-Flex FRC-754 List 4
Operational Capabilities
The FRC-754 List 4 channel unit provides eight loop start or ground start POTS interfaces between the RT and
subscribers, and performs the following functions:
•64 kbps A-Law PCM encoding
•applies ringing voltage
•generates forward disconnect
•generates 12 kHz or 16 kHz meter tones
•detects an off-hook or ring-trip condition
•connects a subscriber loop to a metallic bypass pair
•protects against secondary surges
The subscriber line battery is supplied by a constant current supply. It is sufficient to operate a telephone set over
the indicated loop length. The battery feed can be disconnected and the loop opened to release subscriber
equipment when a forward disconnect signal is received fromthe FLC-704 List 4 COT line unit. The battery feed
polarity can also be reversed as a physical signal of far end supervision.
Circuit Operation
The following paragraphs define the FRC-754 List 4 circuit operation when using loop start for subscriber lines
or ground start for PBX lines. Each FRC-754 List 4 circuit has an associated LED that indicates when the line is
off-hook, idle, ringing, or under test (see Table 1 on page 2).
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 2
on page 4 for circuit interactions):
•loop current flows and is detected by the FRC-754 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 FRC-754 List 4 COCU FRL-754 List 4 RTCU Subscriber
Circuit Idle No ringing ⇒No ringing ⇒
⇐On-hook ⇐On-hook

363-754-104-01, Revision 01 Product Overview
PG-Flex FRC-754 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 FRC-754 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 FRC-754 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 FRC-754 List 4 COCU FRL-754 List 4 RTCU Subscriber
Circuit busy No ringing ⇒No ringing ⇒
⇐Off-hook ⇐Off-hook

Product Overview 363-754-104-01, Revision 01
6 June 22, 1998 PG-Flex FRC-754 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 and Tip 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 occur simultaneouslyon the same line). Glare occurs when 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 FRC-754 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 FRC-754 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