Toshiba Strata Dk14, Dk40i, Dk424 Installation And Maintenance Manual

							Strata DK I&M    5/996-1
DK424 T1
DK424 T16
This chapter covers information on using T1/DS-1 interfacing. It is available for the DK424. T1/
DS-1 interfacing is not available for the DK14 and DK40i.
Channelization
The Strata DK424 RDTU PCB provides T1/DS-1 interface for up to 24 channels. Each channel 
can be individually set for loop start, ground start, Tie, or DID line operation (voice only, not data 
lines). Each RDTU can be set in system programming to activate (1~8), (1~16), or (1~24) 
channels (lines). Fractional increments of 4, 12, and 20 are also possible but the RDTU will still 
assign 8, 16, or 24 channels respectively in system software.
Example: If only 12 channels of fractional T1 are used, assign RDTU as a 16 channel RDTU. The 
system will assign 16 CO lines to the RDTU even though only 12 CO lines will be used. To busy 
out unused RDTU channels (see “System Programming for T1” on Page 6-3, Step 4). Use Program 
03 to set the quantity of RDTU channels.
Slot Assignments
Up to eight RDTU PCBs can be installed in a DK424 to provide up to 192 lines. RDTU PCBs can 
be installed in the same cabinets that have analog type CO line PCBs installed. RDTU PCBs must 
be placed in designated slots in each of the DK424 cabinets. (See Tables 4-4 and 4-5 in Chapter 4 
– DK424 Configuration for RDTU slot installation rules)
If an RDTU is installed in a cabinet (in some cases one or two slots to the right of the RDTU may 
not be used in that cabinet) the number of unusable slots in a cabinet (none, 1 or 2) depends on 
which slot the RDTU occupies and how many lines (8, 16, or 24) the RDTU is programmed to 
provide. Use Program 03 to set the RDTU slot assignments and Channel quantities (Code 71 = 8 
ch., Code 72 = 16 ch., and Code 73 = 24 ch.). 
						

							DK424 T1
RDTU T1 Interface Unit
6-2Strata DK I&M    5/99
RDTU
T1 Interface Unit
System:DK424
Circuits per PCB:8, 16, or 24 channels
Interfaces with:ground start CO lines
loop start CO lines
DID or Tie lines
Older Version(s): none
RDTU is configured for Tie or DID lines and an RRCS must be installed for DTMF operation. 
LEDs on the RDTU show a continuous status of RDTU operation.
NoteEach Tie or DID line decreases the system’s station port and CO line capacity by one.
A Strata DK424 system operating with an RCTUE/F can support  up to eight RDTU PCBs. 
RCTUC/D common control unit supports up to six RDTU PCBs. The RCTUB and RCTUBA/BB 
support up to two RDTU PCBs. The RDTU cannot be installed in a system operating with the 
RCTUA.
RDTU controls and interface connectors are shown in Figure 6-1 and described in Table 6-1.
The RDTU requires installation of a customer-provided Channel Service Unit (CSU). Refer to 
“Installation Guidelines” on Page 6-10 for CSU installation.
Testing procedures (local loop back and remote loop back) are in “Loop Back Testing” on Page 
6-16.
SW1 Equalizer Switch and Loop Back Jumpers (Internal Option)
The distance between the DK424 cabinets and the CSU (or other customer premise T1 circuit) 
determines the setting of the SW1 Equalizer Switch. The SW1 switch consists of a bank of smaller 
switches, S1~S7.
äSet the SW1 switch as follows:
NoteThe maximum distance between the RDTU and the CSU or other T1 circuits can not be 
more than 655 feet (see “RDTU to PBX T1 (Separated More Than 655 ft.)” on Page 6-11).
ModeFeet from DK424S1S2S3S4S5S6S7S8
Short 0~150 ON OFF OFF OFF OFF OFF OFF N/A
Medium 151~450 OFF ON OFF ON OFF ON OFF N/A
Long 450~655 OFF OFF ON OFF ON OFF ON N/A 
						

							DK424 T1
RDTU T1 Interface Unit
Strata DK I&M    5/996-3
DK424 T1
RDTU Installation
Installing an RDTU (T1) into a Strata DK424 requires a number of system programs to be run. 
Toshiba recommends running these programs in the order listed before actually installing the 
RDTU into the system. This allows the RDTU to function immediately, including self-check loop 
back testing and normal operation, when it is inserted into the system.
ä
To install an RDTU PCB
1. Set jumper wire plugs P1 (LB), P2, P3, and P4 to the OFF position. See “Loop Back Testing” 
on Page 6-16 for loop back testing procedures.
See “SW1 Equalizer Switch and Loop Back Jumpers (Internal Option)” on Page 6-2 for the 
appropriate SW1 equalizer switch setting.
2. Insert the RDTU (component side facing right) into the appropriate slot and apply firm, even 
pressure to ensure proper mating of connectors. (See “Slot Assignments” on Page 6-1 and 
Chapter 4 – DK424 Configuration, Worksheet 2 for RDTU slot assignment 
recommendations.)
3. After installing the RDTU, gently pull the PCB outward. If the connectors are properly mated, 
a slight resistance is felt.
System Programming for T1
1. Run Program 03: Assign the number of RDTU channels used and the cabinet slot number into 
which the RDTU will be installed (see “Channelization”
 and “Slot Assignments” on Page 
6-1). If 1~8 channel are required, assign code 71, if 1~16 channels are required, assign code 
72, or if 1~24 channels are required, assign code 73 to the RDTU slot. Also, assign RRCS 
code to RCTU if RDTU Tie/DID channels are DTMF.
Important!Special consideration must be taken when installing Tie or DID T1 channels (see 
Worksheets in 6.
2. Run Program *41-2: Assign each channel for loop start, ground start Tie (Immediate or Wink), 
or DID (Immediate or Wink). See Program *41-2 record sheet (unused channels can remain as 
initialized—loop start).
3. Turn system power supply OFF (five seconds) and ON to activate Program 03 and *41-2 
program data. 
NoteThese are the only programs relating to RDTU operation that require system power to be 
cycled OFF and ON.
4. Run Programs 16, 40, 39: If an RDTU is connected to a fractional T1 circuit and all the RDTU 
channels (8, 16, or 24) are not used, busy-out the unused CO lines from all line groups 
(Program 16), all telephone buttons (Program 39), and restrict all stations from accessing the 
unused lines (Program 40). 
Example, if the Network fractional T1 provides 12 channels, set the RDTU connected to this 
T1 for 16 channels in Program 03 (with code 72). If this RDTU is the first CO line PCB in the 
system, the RDTU CO lines will be numbered 001~016. Use Programs 16, 39 and 40 to deny 
use of all unused lines (i.e., lines 13, 14, 15, and 16). In this case the first 12 lines are usable; 
lines 13, 14, 15, and 16 cannot be used. The CO lines on the next CO line PCB (any type) 
following the RDTU PCB will start numbering at line 017.
5. Run Programs 15 and 30: If RDTU Tie and/or DID are dial pulse: Run Program 15-1, LED 
ON for each DP Tie/DID line and run Program 30, LED 11 ON for each Tie/DID station port. 
						

							DK424 T1
RDTU T1 Interface Unit
6-4Strata DK I&M    5/99
6. Run Program 17.
©LED 01: For RDTU Tie lines, set LED01 to allow (ON) or deny (OFF) Page and Voice 
Announce on incoming calls to DK424 stations from the far end T1 Tie line stations. This 
option (LED01) does not apply to RDTU DID lines—Page and Voice Announce is always 
denied to incoming DID calls because of FCC “answer supervision” rules.
©LED 02 (Wink/Immediate): This assignment is for RDDU, REMU, and PEMU lines only; 
it does not apply to RDTU Tie or DID lines. Use Program *41-2 to assign RDTU lines for 
wink or immediate start.
©LED 03: Toshiba recommends turning this LED ON (initialized state) for all RDTU DID 
lines to enable incoming DID calls to camp-on busy stations. This is also necessary to 
allow more than one DID line to ring into a station simultaneously. LED03 does not apply 
to RDTU Tie lines.
©LED 04: For RDTU Tie lines, LED04 is normally OFF to enable dial tone to be received 
from the far end Tie line when calling DK424 stations. For DID lines LED04 is normally 
ON so RDTU DID lines do not send dial tone to the CO Run *41-1: Use this program to 
assign the RDTU (T1) Line Coding method (B8ZS or AMI) and signal Framing format 
(SF or ESF). Contact the account representative of the company that is providing the T1 
span line (Local Central Office or Long Distance Provider) to determine which line 
Coding and Frame format will be used.
©Line Coding: The DK424 RDTU supports T1/DS-1 transmission of Voice and Analog 
Data (using modems) using Alternate Mark Inversion (AMI) with Zero Code Suppression 
(ZCS) or Bipolar Eight Zero Substitution (B8ZS) line coding. B8ZS provides clear 
channel capability, which allows frame information bits to carry any combination of ones 
and zeros—a feature needed for T1/DS-1 transmission of digital DATA (DK424 does not 
support transmission of digital DATA over RDTU T1/DS-1 at this time). 
©As of this writing, most Telcos provide AMI line coding which is adequate for DK424 
RDTU voice transmission; however, B8ZS may be required by some long distance 
providers, college campus private networks, or customer premise end to end T1 
connections. AMI and B8ZS are adequate for DK424 Voice T1/DS-1 transmission.
©Framing: As of this writing, D3/D4 Superframe (SF), or Type I and Extended Superframe 
(ESF), or Type II T1/DS-1 is offered by most all local Telcos and Long Distance 
Providers. Normally the local Telco will provide SF, which is adequate for DK424 voice 
(and modem type data) transmission. Long distance providers may offer either SF or ESF. 
ESF provides a more enhanced method of error checking that SF; however, the Channel 
Service Unit (CSU) must be compatible with ESF and may cost more than a SF only CSU. 
ESF circuits have the additional power of Cyclic Redundancy Checking (CRC), which allows 
end-to-end monitoring of T1 circuit performance. ESF, T1 performance monitoring normally 
requires that a person be specially trained for this function. SF and ESF Frame format is 
adequate for DK424 Voice (and modem type data) T1/DS-1 transmission.
7. Run Programs *41-3 and -4: These programs allow the RDTU Transmit and Receive (Volume) 
level to be adjusted by changing the RDTU built-in digital PAD value between +6 decibels 
(dB) and –15 dB. Transmit and Receive levels are individually adjustable on each RDTU (all 
channels will have the same level). Toshiba recommends using the initialized levels (Receive 
–3 dB/Transmit –6 dB) upon initial installation. Adjust the RDTU digital PAD as required 
while testing each RDTU T1 channel.
8. Run Program *42 Series—T1 Span Timing Reference Assignments
Timing references for T1 RDTU PCBs are made with the Program *42 series. The RDTU (T1) 
timing (or synchronization) program options determine how the DK424 system digital voice  
						

							DK424 T1
RDTU T1 Interface Unit
Strata DK I&M    5/996-5
DK424 T1
transmission path (time-switch) is synchronized with the far end digital system transmission 
path. For proper T1 operation, the equipment at each end of a T1 span line must be 
synchronized. 
The DK424 time-switch is synchronized (as slave) to the T1 span equipment on the other end 
of the T1 line by the RDTU PCB designated as the Primary Reference in Program *42-1. 
When a RDTU is connected to a Telco or Long Distance Provider T1 span line, the RDTU in 
the lowest slot number should be assigned as the Primary Reference RDTU (*42-1, DATA = 1 
FOR THIS RDTU).
If a malfunction occurs and Primary Synchronization is lost, the DK424 automatically 
switches modes and synchronizes to the T1 span connected to the RDTU PCB designated as 
the Secondary Reference (provided that there are two RDTU PCBs installed in the DK424) 
(see Figure 6-1). 
						

							DK424 T1
RDTU T1 Interface Unit
6-6Strata DK I&M    5/99
1675
Synchronization
Circuit RDTU(2) (Secondary Ref)
Digital Voice Path
Synchronization
CircuitRDTU(3)
Span
Line 3
T1 Span Clock Not
Synchronized Properly with
Stratum 1 Clock Source Digital Voice PathOther
T1
Provider Span
Line 1Telco
Central
Office
T1
Span
Line 2AT&T
Long
Distance
T1Stratum 1
Clock
Source RDTU(1) (Primary Ref)
SS
1
SS2
SS3
DK Digital Transmission Voice Path
PDKU Digital
Telephone
PEKU Electronic
Telephone
RSTU Standard
TelephoneStrata DK424
RCTU PCB
Synchronization
Circuit
ClockTime
Switch
Synchronization
Circuit
Digital Voice Path
Figure 6-1 RDTU Primary/Secondary Reference Block Diagram
Notes
lPrimary Reference Synchronization:
In this diagram RDTU(1) is the primary reference, its synchronization circuit sends the clock 
reference from the TELCO T1 span to the DK424, to the RCTU synchronization circuit, via 
RDTU1 Software Switch (SS). The RCTU(1) clock synchronizes the DK424 digital 
transmission voice path (via RCTU time switch) to the TELCO/STRATUM1 clock source.
lSecondary Reference Switch-Over:
If the primary reference T1 RDTU(1) fails, the DK424 will automatically open the RDTU(1)  
primary synchronization circuit (SS1) and close the RDTU(2) secondary synchronization 
circuit (SS2). At this time, the DK424 digital voice path will be synchronized to the AT&T/
STRATUM1 clock source.
lSlip example:
In the above diagram the “Other T1 Provider” is not synchronized to the STRATUM1 clock 
source properly – Slip problems will occur on RDTU(3) T1 channels. 
						

							DK424 T1
RDTU T1 Interface Unit
Strata DK I&M    5/996-7
DK424 T1
If there are two RDTU PCBs installed, it is recommended not to install the Primary and 
Secondary Reference RDTU PCBs in the same DK424 cabinet if possible (although both 
Primary and Secondary Reference RDTU PCBs can be installed in the same cabinet). The 
Secondary Reference RDTU should also be connected to a Telco or Long Distance Provider 
T1 span (*42-2, Data = 2 for this RDTU). 
If the equipment on the other end of the DK424 T1 lines should synchronize to the DK424 
clock source, then blanks should be entered in Program *42. In this case, the DK424 clock 
runs free and is considered the Master Synchronization provider. The DK424 can be assigned 
as the Master (free run) clock provider if the far end equipment connected to the RDTU T1 
span is a Customer Premise type equipment and it is not synchronized to some other T1 
provider (i.e., PBX, Channel Bank, Key/Hybrid or other DK424). In this case (when the Telco 
network is not connected), either the DK424 RDTU span or the far end equipment can be the 
Master (synchronization clock provider).
©Program *42-1, Primary Timing Reference Assignment: Assign the Primary Timing 
Reference with this program.
©Program *42-2, Secondary Timing (Backup) Reference Assignment: Assign the Secondary 
(Backup) Timing Reference with this program.
©To assign RDTUs for the Master Clock Provider, leave Programs *42-1 and *42-2 blank. Press 
button/LED01 to enter blanks.
Important!The Digital Network is connected to clocks with various degrees of precision called 
stratum levels from Stratum 1 (highest level of accuracy) to Stratum 4 (lowest level) 
as follows:
•Stratum 1—Public Telephone Network clock located in Hillsboro, Missouri.
•Stratum 2—Normally associated with #4 ESS Toll switches.
•Stratum 3—Normally associated with #5 ESS Central offices.
•Stratum 4—Normally associated with Digital PBXs.
•If a DK424 RDTU is programmed as the Primary Synchronization Clock 
reference, the clock provider connected to this RDTU should be a reliable clock 
provider, such as a Telco or common carrier (Example—AT&T). All other T1 span 
lines connected to RDTUs in the DK424 must be synchronized to the same clock 
source as the AT&T span line. If a T1 span line is not synchronized with the 
primary clock provider (AT&T, for this example), then DK424 lines assigned to 
this T1 span line (RDTU) may experience “slip” problems.
9. The programs in Steps 1~8 are described for specific RDTU application programming. Also 
refer to “System Programming for T1” on Page 6-3. Run the programs as they apply to RDTU 
CO line applications.
  
						

							DK424 T1
RDTU T1 Interface Unit
6-8Strata DK I&M    5/99
RDTU Programming
The following programs select the number of channels supported by the RDTU and assign line 
operation for the individual channels.
Notes
lRDTU Tie lines can route per Program 04 [DN] assignment or Program 71 and 72 DNIS 
assignments (see Program 17, LED 05).
lRDTU DID lines can route per Program *09 assignments or Program 71 and 72 DNIS 
assignments (see Program 17, LED 05).
Program 03: Specify Code 71 for an 8-channel RDTU, Code 72 for a 16-channel RDTU, or Code 
73 for a 24-channel RDTU. (The 8-channel RDTU is the default.) Also, the Dual-Tone Multi-
Frequency receiver (RRCS) must be installed and assigned if RDTU Tie and/or DID lines are 
DTMF.
NoteIf the T1 is 8 channels, skip Program 03 and run Programs 91, 91-1 or 91-9  instead.
Program 04: Tie line digit translation (if T1 channel is Tie). Also see Programs 17 and 71~72.
Program *09: Use to translate DID digits to ring designated stations. Also see Programs 17 and 
71~72.
Program 10-1: Use to enable or disable Two-Line Conference and Direct Inward System Access 
(DISA).
Program 15: Use to assign DTMF/Dial Pulse dialing, DISA, and additional attributes to each line. 
Automatic Release (AR) assignments only need to be made for loop start lines; AR is not needed 
for ground start lines. Also use to enable DID lines with DNIS and ANI options.
Program *15: Use to make tenant assignments.
Program 16: Use to assign lines to line groups.
Program 17: Use to assign Tie/DID Auto Camp-on, and second dial tone.
Program *17: Use to assign intercept port for DID line calls to wrong or vacant numbers.
Program 30: If RDTU Tie and/or DID lines are Dial Pulse (DP—Program 15-1), then Program 30, 
LED 11 should be ON for the Tie/DID station port numbers; if they are DTMF, LED 11 should be 
OFF.
Program 39: Use to assign line access buttons to digital and electronic telephones.
Program 40: Use to assign station access to lines (incoming and outgoing).
Program 41: Use to assign station access to lines (outgoing only).
Program *41 Series: Run to assign RDTU channel line operation, and coding and framing modes.
Program 42-0, 1~8: Use to assign behind PBX/Centrex operation to each line.
Program *42 Series: Use to assign timing reference for RDTUs.
Programs 45~48: Use to define Toll Restriction for any line.
Programs *50, *51, *52: Use to define Caller ID/ANI assignments.
Programs 50~56: Use to define Least Cost Routing assignments.
Program 59: Use to assign T1 lines to attendant console buttons. 
						

							DK424 T1
RDTU T1 Interface Unit
Strata DK I&M    5/996-9
DK424 T1
Program 71~74: These programs are used in place of Program *09 to assign DID/Tie/DNIS line 
ringing destinations.
Program 71 (1~5): Tie/DID DNIS assignment (optional used in place of *09. Also see Program 
04).
Program *71~*73: Tie/DID telephone/[DN] ring assignments.
Program 78: Use to assign special ringing of lines: includes Night Ring Over Page, DISA, Remote 
Maintenance via the Internal Maintenance Modem (IMDU), and Built-in Auto Attendant.
Programs 81~89: Use to assign loop and ground start RDTU CO lines to ring selected stations on 
incoming calls.
Programs *81, *84, *87: Assigns [DN] LEDs to flash when CO line rings a telephone.
Table 6-1 RDTU Controls, Indicators, and Connectors
Control/Indicator/ConnectorType of ComponentDescription
SW1 Equalizer Setting Switch 8 2-position slide switchesSets line length between RDTU and CSUs or 
other T1 (max 655 ft.).
P3 (not used) 3-terminal jumper plug This jumper plug is reserved for future use.
P4 Remote Loop Remote Mode 
jumper plug3-terminal jumper plugSets RDTU for Remote Loop Back mode test 
procedure.
P1 and P2 Loop Back jumper plug 3-terminal jumper plugSets RDTU for self check or Network/CSU 
loop back check.
ON OFF
ON OFF
ON
OFFON
OFF
ON
S1 OFF S8
1669
LED Status Indicators 
BSY
FALM
MFALM
YALM
BALM
PSYNC
SSYNC
Equalizer Setting
SwitchP4: Remote Loop Back Test
P1
P2RDTU Self Test
Network/CSU Test
SW1
CD3
CD7
CD6
CD5
CD4
CD2
CD1LLB
P6
RDTUP3: Future Use
P3 P4 RLB
LB P2 P1
Backplane
Connector Female 
Amphenol 
Connector
Figure 6-2 RDTU Printed Circuit Board 
						

							DK424 T1
Installation Guidelines
6-10Strata DK I&M    5/99
Installation Guidelines
1. Read “Channelization” on Page 6-1 before proceeding to Step 2.
2. Run RDTU T1 related system programs as described in “Applications” on Page 6-11.
3. Set P1 and P2, loop back jumper to the ON position for RDTU self test (see “RDTU Self Test” 
on Page 6-16). Refer to “Hardware and Cabling” on Page 6-13 for the appropriate SW1 
Equalizer Switch setting and set SW1 to the setting that matches the RDTU cable length.
4. Install the RDTU PCB per instructions Page 6-3.
NoteEnsure the RDTU’s component side is facing right when installing it in the cabinet.
5. Run the RDTU self check per “Network/CSU T1 Span Test” on Page 6-17. After self check 
passes, put P1 and P2 to the OFF position for normal operation and insert the RDTU PCB 
back into the appropriate slot.
6. Install CSUs and wire them to the RDTU and Network Interface Unit (NIU) or Customer 
Premises T1 circuit as required. See “System Programming for T1” on Page 6-3
.
NoteBefore connecting the CSU to the Telco line, notify the T1 provider. You should also 
notify the T1 provider before disconnecting the CSU.
7. Perform CSU to RDTU and CSU to Network loop back testing per CSU documentation and 
“Loop Back Testing” on Page 6-16.
Notes
lLocal loop back and network loop back test cannot be performed simultaneously.
lCSU local/network loop back is a function of the CSU, not all CSUs provide this function – 
see CSU I&M documentation for CSU loop back test procedures.
8. After loop back testing is complete and synchronized with the far end T1 circuit, perform test 
calls on all RDTU lines. (Use the troubleshooting procedures in “T1 Fault Isolation” on Page 
6-20 to help correct problems.)
9. Check T1 performance periodically for transmission errors using the “T1ERR” test. This 
requires a local or remote maintenance terminal connected to the PIOU or PIOUS PCB (local) 
and IMDU or Hayes-compatible modem (remote).
Transmit Receive CSU NIU
Receive Transmit
Local Loop Back Network Loop Back DK424 RDTU
Network
1674
Figure 6-3 CSU Local and Network Loop Back Tests