E.F. Johnson Company 3000 SERIES, Setup And Alignment Manual

Page: 149 / 214

17-1
LOGGING ENCODER MODULE (LEM)
SECTION 17 LOGGING ENCODER MODULE (LEM)
17.1 DESCRIPTION
Refer to 3000 Series Switch Service Information
manual, Part No. 001-3139-102, for the component
layout, parts list and schematic. Refer to Figure 7-1 for
the Basic Board block diagram. The Logging Encoder
Module (LEM) is the interface that performs the data
collection and outputs of information for recording
voice traffic.
The LEM communicates with the other modules
via the Intra-Terminal Data Bus (IDB) and monitors
the Channel Status Bus (CSB) for the groups set up to
use the LEM. The LEM is configured to monitor up to
five channels for information. The LEM converts the
CSB information for the five channels and outputs
1200 baud AFSK to a logging recorder. There may be
up to six LEMs in a Switch to cover up to thirty
channels.
Figure 17-1 DATA BUS BLOCK DIAGRAM
CIMs CCMs
(NetIDB)
DATA BUS
INTRA-TERMINAL
NETWORK
(NetCSB)
STATUS BUS
CHANNEL
NETWORK
NETWORK
INTERFACE
MODULE
NetNIM
(CIB)
CHANNEL INTERFACE BUS
CONVENTIONAL
CHANNEL
MODULE
INTERFACE
CHANNEL
MODULE
INTRA-TERMINAL DATA BUS (IDB)
(CIB)
CHANNEL INTERFACE BUS
CHANNEL STATUS BUS (CSB)
DISPATCH
MODULE
CHANNEL
DCMs
PSTN OR PABX
TELEPHONE
MODULE
INTERFACE
TIMs
NETWORK
SYSTEM
MODULE
SNMs
SYSTEM NETWORK BUS (SNB)
CALL
PROCESSOR
WIDE
MODULE
AREA
WAMs
LOGGING
MODULE
ENCODER
LEMs
LOGGING RECORDER
ETHERNET
BUS