GTE Omni Si Database Technical Practices Issue 1 Manual

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REMOTE DATA30.0 Remote Processors (RPs) such as the APMsPROCESSORS(Asynchronous Packet Managers), 
DFPIAPM (Digital
SYSTEMFeaturephone with Asynchronous Packet Manager), and 
SPMsCONNECTIONS(Synchronous Packet Managers) are normally connected as
shown in Figure 30.1.
The asynchronous and synchronous processor (APM, 
DFPIAPM,SPM) can be located remotely to reduce traffic within the system.
The remote processors eliminate the need for in-house
processors.
MPP
I==
I
I IVOICE , VOICE ,
PACKET PACKET
LINE LINEI I
CARD 2 CARD 2I I
I
I
II
11
II
IIVOICE IVOICE IPACKET 
;
LINECARD 
;
SYNCHRONOUS
i
x 15
PUBLICDATA
NETWORK
KEY:
mnRS-232-C CONNECTION
:aRS-232-C OR V.35 CONNECTION
B TWISTED PAIR
Figure 30.1
Connection of Data Devices
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APM (ASYNCHRONOUS31.0 The microprocessor controlled APM (Figure 31 .l) pcovidesPACKET MANAGER)the interface between the asynchronous data equipment
EC-221 79-A(terminals, personal computers, etc.) and the VPLC (FB-17226)
card or VPLC2 (FB-17426) card. Each APM connects to one
asynchronous data device.
SVR 5210TEST
\,
FRONT VIEWS
REAR VIEWI
II\II
LINEDATA1’1 ’RESET
OUT
/
IN
DCEDTE
IFigure 31.1APM
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The APM Assembly EC-22179-A0 Is used for devices that require an asynchronous W-232-C
type interface
l Supports devices that operate at speeds up to 19.2 Kbps
The VPLC (FB-17226) that is used to support an APM is
configured as a type VPLC 0 in data base, allowing all 8 ports of
the card to be used (see Figure 31.2).
NOTE: The VPLC2 (FB-17246) card, when configured as a type
VP20 card in data base, can support 
APMs, DFP/APMs, and
DFPs.Figure 31.2 APM Connection
I ADMP-A
FB-17229LPB
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The APM, designed for desk-top installation, is housed in a
small plastic case. A telephone can be put on top of the APM;
cable connections are at the back of the APM. Each APM
communicates with the system over a single twisted wire pair.
This connection provides for continuous two-way transfer of
data only (no voice). Using 26 gauge wire, the maximum
distance from the APM to the system is 3000 feet. The maximum
distance from the APM to the terminal equipment is 50 feet. The
twisted pair (tip and ring) connection maximum distance between
the APM and the system is 3,000 feet at 26 gauge. The
maximum distance between the APM and its data equipment is
50 feet.
The APM operates from 115 VAC through a step down
transformer (to 22 VAC).
The APM supports one single-speed asynchronous data device
operating at speeds of 110, 300. 4 2C3, 2400. 4800, 9600 baud, or
19,200 BPS (bits per second). For 
RS-232-C compatible
signals (ASCII) to be transmitted to the data system, it must first
be converted into X.25 packets. The X.25 packet then must be
broken down into 11 byte self-routing mini-packets for
transportation to the system (Figure 31.3).
The APM contains an 8-bit microprocessor memory, 16K of
parity protected RAM, 8K of ROM, and a UART (Universal
Asynchronous Receiver/Transmitter). Seven 
RS-232-C/V.24data set signals can be controlled. The AMP contains the 
mini-packet receiver/transmitter and line driver circuits used to
communicate with the system. The ROM (Read-Only Memory)
in the APM contains all programs necessary to boot the APM
from the switch, and debugging and limited hardware self-tests.
The RAM in the APM provides the operational code needed to
communicate via the data system and is used for temporary
storage, buffers, and operational parameters.
The APM performs PAD (Packet Assembler/Disassembler)
functions as well as containing the CRC (Cyclic Redundant
Checking) error detect logic (see Figure 31.4).
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distance
RS-232-C
maximum
distance
*- 3000’mini-
packets
m
VPLC -
Figure 31.3
Transport of Mini-Packets
S-298
8187The protocol that governs the function of the PAD is X.3. The X.3
protocol provides a set of values or parameters that characterize
the operations of the terminal that is paired with the APM.
X.3 Parameters31.1 The X.3 parameters define the following basic functions of
the data terminal:
Q Packet Forwarding
? Break Handling
8 Flow Control
@ Device Specific Characteristics
@ Local Editing
@ Local Echo
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digital bit stream
APM
packetizing
datadata packets
CRC
address
(control)
(control “to”)rrgure 31.4ivmwacKeT: rrotocoIThere are eighteen standard X.3 parameters. The 
OMNIrequires an additional seven non-standard parameters, which
are referred to as local parameters. The X.3 parameters are
defined as follows:
Parameter 1 
- Escape from Data Transfer
Parameter 2 
- Echo
Parameter 3 
- Selection of Data Forwarding Signal
Parameter 3 
- Selection of Idle Timer Delay
Parameter 5 
- Ancillary Device Control
Parameter 6 
- Control of Pad Service Signals
Parameter 7 
- Selection of Operation of the Pad on Receipt of
the Break Signal
Parameter 8 
- Discard Output
Parameter 9 
- Padding After Carriage Return
Parameter 10 
- Line Folding
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Parameter 11 - Binary Speed
Parameter 
42 - Flow Control of the Pad by the Start-Stop Mode
DTE (Data Terminal Equipment)
Parameter 15 
- Editing
Parameter 46 
- Character Delete
Parameter 17 
- Line Delete
Parameter 18 
- Line Display
Local Parameters31.2 In addition to the eighteen X.3 parameters the system
operates under seven local parameters
@ 0 - Escape to Local Parameters
e 1 - Profile ID (Terminal ID)
@ 2 - Eight Bit Transparency
@ 3 - Parity
@ 4 - Full Duplex
@ 5 - Interval Timer
0 6 - Echo Mask
An APM may be connected to a modem for access to the public
switched network. In this case, it is necessary that the
characteristics of the modem on each side of the connection
match.
The APM contains the following switches and status indicators:
s-300
@ LINK Indicator. The LINK indicator shows whether the APM is
in a test condition or is receiving/transmitting mini-packets.
@ CALL Indicator. The CALL indicator shows whether the APM is
in a call setup or 
loopback condition.
0 TEST Switch. The test switch is used to send an event to the
ADMP to test the path to the APM.
0 RESET Switch. The RESET switch resets the APM when
activated.
@ DTE.:DCE Switch. The DTE/DCE switch selects the APM
communication mode of operation. The APM communicates
with terminal 
ecuipment in the DTE mode of operation. The
APM 
communicates with modems in the DCE mode of
operations.
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							Tt-130500-I 001SPM (Synchronous32.0 The microprocessor-controlled SPM (Figure 32.1)
provides
Packet Manager)the interface between the synchronous X.25 data equipment
(EC-221 78-A/B)(Public Data Network, Host Computer, etc.) and the VPLC FB-17226 card or the VPLC2 FB-17246 card. Each SPM connects
to one synchronous X.25 data device.
SVR 5210FRONT VIEW
GTEX.25 TESTSWITCHX.25
ACTIVELINKLINK
REAR VIEW
-*“-t-------~~LINEDATA
r-7OUT
I
!N
DCEDTEI
Figure 32.1SPM (Synchronous Packet Manager)
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Two versions of the SPM are available:
l Assembly EC-22178-A (Figure 32.1)- Required by devices that use an RS-232-C/V.24 type
interface.
- This assembly supports devices that operate at speeds up
to 19.2 Kbps.
- The VPLC (FB-17226) used to support the EC-22178-A,
is configured as VPLO in data base allowing all 8 ports of the
card to be used.
NOTE: The VPLC2 FB-17246 card, when configured as a VP20
card in data base, can support low-speed 
SPMs as well as
DFP/APMs and APMs.l Assembly EC-22178-B (Figure 32.1)
- Required by devices that use an V.35type interface.
- This assembly supports devices that operate at speeds up
to 64 Kbps.
- The VPLC (FB-17226) used to support the EC-22178-B,
is configured as 
VPLl in data base allowing it to use only
two ports on the card. It is necessary to reduce ports
available for high speed devices due to throughput
requirements.
NOTE: The VPLC2 FB-17246 card, when configured as a VP21
card in data base, can support two high speed 
SPMs.The SPM, designed for deskto-p installation, is housed in a
small plastic case somewhat larger than the APM. Cable
connections are made at the back of the SPM.
Each SPM communicates with the system over a single 
twisted-pair wire. This connections provides for continuous two-way
transfer of data only (no voice) information. Using 26 gauge wire,
the maximum distance from the SPM to the system is 3000 feet.
The maximum distance from the SPM to the terminal equipment
is 100 feet. An SPM is locally powered over a separate twisted
pair.
The SPM operates from 115 VAC through a 
stepdown
trznsformer to 24 VAC. The SPM supports up to 256 virtual
circuits allowing for up to 256 multiple calls over the 
SPM’stwisted pair line.Multiple virtual circuits are maintained by the
logical channel numbers and device numbers that are assigned
to each data call by the SPM.
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