Remote RAN for 128-port using Motorola DSU/CSU stuck at P1


 AIX 4.1.4
 Model 7025-f30
 ISA 128-port adapters
 Motorola DDS/MR64 DSU/CSU modems

 Customer has a remote ran that is at P1 and he cannot get to work.

 The 128-port adapter cards are showing up with the lsdev command.  I 
 had the customer go into smit and look at the configuration.  He has
 node 1 rs232-modem
 node 2,3,4 as none.

 This is correct for this setup (only one remote ran on line).
 He is using motorola uds modems (dsu/csu).  He has had them checked
 out by Motorola and they can loopback fine.  I explained that P1
 means that we aren't getting any signal from the host (risc) at all.
 He is getting another set of modems in the morning to try.  I suspect
 that this is a cabling problem.   The customer has all the software


 Customer has talked with AT&T and the line is standard dds line and
 provides no clocking.  Motorola says there are only 3 modes for timing:
 external, internal, and dds.  I still don't know what clocking is
 used in dds mode.  The customer put the modems back to dds and changed
 smit.  It now is showing AC on the local and still p1 on the remote.
 The customer rebooted: currently the local ran is p2 and remote ran
 p1.  I am having the customer power off the remote ran to see if the
 local one comes to ac. 

 The local ran came to AC when the remote ran was turned off.  We
 turned it back on and the remote ran still just stayed at P1.
 We tried several different settings for timing on the local modem
 (remote in dds mode).  There are 3 altogether: external, internal, and

 Customer will callback on monday and conference in with Motorola.
 He will also try setting the "grounding signal"  jumpers in the 
 modem to "chassis ground".  

 Customer called and would like to fax the manual for the motorola UDS
 DDS/MR64 modems to see if there was anything in there that I would
 recommend he try to set.  I called the customer back and explained
 that I don't see anything readily apparant.  I suggested the the
 customer consider purchasing the Inter Systems Mux Eliminator-56
 instead.  THis includes cables, modems, and tech support.  They
 guarantee that they can get it to work.  Customer would like
 to persue this further before doing that.  He has a call in to
 motorola and is expecting a callback from them.  I also gave the
 customer the following information regarding a Motorola MR/56
 modems and some of it's settings.  I am faxing the following
 information to the customer:

                       List of Synchronous Modems

             For 128-Port Adapters to Connect remote RANs.
General Overview of DSU/CSU (or modem connections):

Only synchronous communications are supported using an SDLC protocol.

Neither the 128-port adapter or the RAN supply any handshake signals
(CTS, RTS, DTR, DSR) to the DSU/CSU or modem.  These cables may need to
be customized based on the individual modems used.

Often the DSU/CSU or modem needs to have Forced RTS or Forced DTR set.

The requirement is to have one only TxC source for the sync modem link.

The performance of the entire line (both local and remote users) 
depends on the speed of the link.  It is very unwise to use 9600 BAUD
modems as the service for all users must be divided into this 9600 BAUD.
This includes the data and the packet overhead.  With some applications,
there is a packet for each character sent creating a large overhead, with
printing and screen refresh this is not a problem.

Setting SMIT settings is described in "System Management Guide:
Operating System and Devices", GC23-2486, chapter 21.

Sometimes debugging can be better done using a tool called 'dpa' 
which is available from the "AIX Systems Center" for customers of
support line.  This tool will help identify the types of errors on the
line, and can also be used as a remote breakout box for all ports on
all RANs.

When using RS/232 Modem's or DSU/CSU's the distance between the Modem
and the RAN or Adapter should not exceed 12 feet on each end for best
operations.  The reason for this restriction is that the RS/232 connection
is not differential.  For longer distances between the computer and the
modem or between the modem and the RAN, use RS/422 modems or DSU/CSU's.
                        Digital Sync Modem (CSU/DSU)

It is a requirement that in Digital circuits that the TxC be derived from
the Network.  The speed of the line, the modems and the SMIT setting for
the adapter line should all be set to the same value.  If the line is a
56 KB line, a setting of 57.6 in SMIT will usually work.

Both DSU/CSU (Local and Remote) need to be set to derive their clock
signals from the line.  This may require an EXTERNAL clock setting or
a slave clock setting.

                            Analog Sync Modems 

The first modem has the MASTER TxC CLOCK.  This means that it is usually
set to INTERNAL clocking.  It is recommended that the HOST modem be the
MASTER clock modem.

The second modem is the SLAVE to the Clocking.  This means that it is
usually set to EXTERNAL clocking and sometimes to SLAVE clocking as well.
Some modems use the term TRIBUTARY clocking.

Caution needs to be used with dial up analog lines because if the line
is down for any reason two BAD things will happen.  First, if the system
is rebooted or cfgmgr is run at this time, the RAN on that line will become
'defined' (NOT AVAILABLE).  Second, if any local RAN are also on the line,
they will become unusable while the line is down.
                          List of Successful Modems


Experiences with this modem have been very positive, but it does
require a modification to the NE & NF cables.  This modification is 
to leave pin 5 on the 5 pin end unconnected, and jumper pins 4-6-20 all
together.  Setup for Modem is attached in appendix B.


This company offers a TURN KEY package for $2,495 with 15% dealer
discount on the first order, and 30% on subsequent orders.  This package
includes cables and instructions for hooking up remote RAN's on the 
128-Port including technical support (24 hour a day).  Switch selectable
from 2.4 to 56 Kbps.  Package includes: (2) TPI 4020 DSU's, Cables set
installing up to 4 remote RAN's, plus test cables;  32 Page 
Installation/Users Guide, 5 year warranty.  Digital Loopback and channel
diagnostics capability.  On Digiboard recommended list.  No problems have
been reported to the Support Center for hooking up RANs with these modems.
Contact: David Norwood, Inter Systems, (800) 242-5529

Datatel CSU/DSU:   Cray Systems

DCP3083 RS-422, Full CSU/DSU Capability; DCP3081;
DCP3080 RS-232, Vanilla RS232;
CDP4856 RS-232, DTE Subspeed with bitstuffing, SNMP manager, RAID
adaptable.  This systems are on list supplied by Digiboard.
Formerly Dowty Communications, 15455 Conway Rd.,
Suite 120, Chesterfield, MO 63017
(800)-227-3134, Dallas (214)-394-3343.

Telebit 1600:

On Digiboard recommended list.
Full asynchronous and synchronous compatibility with dial-up V.32 modems.  
CCITT V.42 error control.  Data compression up to 4:1 with V.42bis,
Supports DTE speeds up to 38,400 bps, supports remote configuration 
and diagnostics, pre-set configurations.  Supports both leased line 
and dial-up.
Telebit Inc, 800-835-3248

MicroCom Qx-1632BIS:  Modem Eliminator 9.6

Reported by customer to be a good working solution on the 128-port 
RAN connection.


These modems have worked fine with a single RAN on the line, but 
when several RAN's were added, the LED's would stick at the P2 or P4 
stage of configuration.  Solution is to use the High Performance NE 
& NF Cables listed in Appendix A.
List of Successful Modems                                 Page 2

UDS Digital Data Set DDS/MR56:

Works good at 56 KB with settings in appendix C.

UDS V.32 Modem:

Reported by customer to work well.

UDS 9600A/B:

Customer got this modem to work by using a little trickery.
See appendix E for details.


Worked fine for customer. Force RTS or use cable specification 
for IBM 5822 modem.  Recommend the High Performance cable.
BAT Electronics VRL1 Modem worked fine when Force RTS set.
BAT Electronics


These modems have been made to work with the loaded protocols. 
Protocol 11 (Leased Line Originate) on one and 12 (Leased Line Repeater)  
on the remote modem worked for one (Unknown) model.  In one case
the user had to get the modems connected before turning on the RAN's 
or plugging in the 128-port cable.  In all cases we have worked with, 
this modem has worked when difficulties overcome.
Address  11550 IH 10 West, San Antonio, TX 58230 Phone (512) 558-1910

Adtran DSU56:

With digital leased line, set clocking on all Modem's to 'NORMAL'
and all RAN came up AC.

General Datacom 500C UXR modems:

Customer reported successful installation at 56 KB., but other
customers have experienced problems.

IBM 7855 Synchronous Modems:

Customers have reported these modems to work well.
                Modem's with negative customer experiences

Some modems on this list may reflect the specific customers
capabilities and not necessarily the capabilities of the modem.
However the customer support from the modem vendors in the earlier
list seem to provide better help with the 128-port solution.

Paradyne 3600, 3610, 3500:
These DSU/CSU seem seem to be very sensitive to the cable impedance
and length.  In some cases these modems work well with high performance
cables described in appendix D.

One customer tried to use 3510 in V.35 mode with a rs422 to V.35 
converter, but was unable to get it working even though he has a 
different modem working in a similar fashion at a different customer 
with the 128-Port. This is probably a phone line problem.

Some Customers that have these modems working find that they
work at 19.2 KB, but not at 56 KB.

Multi-Tech MultiModemII DSU/CSU:

Customer had trouble setting up, but it may be his line setup and
converters.  Setup is described in Appendix F.

Multi-Tech Modems:

In general we get lots of calls with customers having trouble setting
up these modems, but no common trend to solution.

DataPhone 2096A:

For one customer, they worked with a single RAN, but not with 
multiple RAN's on the line.  Using the High performance cable described
in appendix A helped the modem work fine.

Codex 3500:

Customers got these to work at lower baud rates, but at 57.6 they 
won't come up.  Better success has been obtained with the high performance
cables described in appendix A.

Codex CS9600, 2382:

Customers are experiencing great difficulties in getting these 
modems to work.  Both are analog modems.

U.S. Robotics:

Noise, and too many errors with both models HSE and Dual Standard
when using standard NE/NF cables.  These modems work well with high 
performance cables described in appendix A.
                         SOURCES for 128-port cabling
 Long distance cables for RAN to RAN

        Cables To Go                    1-800-826-7904
 Most cables for 128-Port not available from IBM

        MicroComputer cables            1-313-946-9700  Mellisa
 64-port to 128-port connectors, and other 128-port cables

        Interconnect Systems Group Inc  1-800-334-4905
        Bob Brunette, Mark Cunningham
 V.35 to RS422 converters

        Supplies many of the cables not supplied by IBM.
 Average cost is $32.00 + 0.45 per foot.
        Black Box Inc                   1-412-746-5500

High Performance NE/NF cables (Recommended length 6 feet)

        Black Box Inc                   1-412-746-5500

        Cables To Go                    1-800-826-7904

        MicroComputer cables            1-313-946-9700  Mellisa

               Appendix A:  High Performance NE/NF Cables

Recommended high performance NE and NF cable:
 - designed to minimize crosstalk
 - The cables are available from Black Box Corp., Cables to Go and
   MicroComputer cables

      ************************ NE Cable ************************
      Pair    System End   Signal         Modem End
              HD-15 Male                  DB-25 Male

      1       1  --------- RxD  --------- 3
                      +--- Sgnd ---+
            * 5       |            |
      2       4  --------- RxC  --------- 17
                      +--- Sgnd ---+
                      |            |
      3       6  --------- TxD  --------- 2
                      +--- Sgnd ---+
            \# 10      |            |
      4       9  --------- TxC  --------- 15
              12 -----+--- Sgnd ---+----- 7
              Shell        Shield         1, Shell
                           RTS      +---  4
                           DSR      +---  6
                           DTR      +---  20

      ************************ NF Cable ************************

      Pair    Modem End    Signal         System End
              DB-25 Male                  HD-15 Female
      1       3  --------- RxD  --------- 6
                      +--- Sgnd ---+
                      |            |      10 \#
      2       17 --------- RxC  --------- 9
                      +--- Sgnd ---+
                      |            |
      3       2  --------- TxD  --------- 1
                      +--- Sgnd ---+
                      |            |      5  *
      4       15 --------- TxC  --------- 4
              7  -----+--- Sgnd ---+----- 12
              1, Shell     Shield         Shell
              4  ---+      RTS
              6  ---+      DSR
              20 ---+      DTR

      Note: (apply to both cables)
      * a 2200 pf cap across pins 4,5         
      \# a 2200 pf cap across pins 9,10
         o Drain wire of cable shield tied to shells on both 
           connector and into pin 1 of the DB-25
         o Each signal is paired with a Sgnd (signal ground).  
           Sgnd tied together at each end of the connector and 
           on pin 7 (DB-25) and pin 12 (HD-15) on the other end.
         o pins 4,6, and 20 tied together. DSR of modem will 
           drive RTS and DTR.
                 Appendix B:  5822-10 CSU/DSU setup

Primary    Secondary
-------    ---------
  1:2         1:2        (Mode = LDM)
  2:1         2:1        (Link = Pt-to-Pt SA)
  3:1         3:2        (Network Function:  1= Primary, 2 = secondary)
  4:1         4:1        (Antistreaming = Disable)
  5:2         5:2        (Network Services = Disable)
  6:1         6:1        (Test Control = Disable)
  7:2         7:2        (Clocking = Internal)
  8:E         8:E        (data Rate = 56000)
  9:2         9:1        (First Address Digit)
  A:2         A:2        (Second Address Digit)

See Part 3: Setting Up and Configuring the 5822-10 chapter in
the users guide.

Cabling for 5822

The High Performance NE/NF cables listed in Appendix A work well
with the IBM 5822.  An alternate lower cost cable that works fine is
described here:

128-Port Controller           RS-232
     or                    Synchronous
RAN "OUT/T" Port              Modem
-------------------        ------------
    15 pin  male           25 pin  male
 RxD     1 ----------------- 3  Rxd
 RxC     4 ----------------- 17 RxC
 TxD     6 ----------------- 2  TxD
 TxC     9 ----------------- 15 TxC  - Transmit clock
 Gnd    12 ----------------- 7  Signal Ground
 Gnd   Shell --------------- 1  Ground  (15 pin end soldered to shell)
                          !- 4  RTS
                          !- 6  DSR   All 3 tied together at modem end.
                          !- 20 DTR
                             5  CTS   Leave unconnected.
  Modified NF Cable
 25 pin male                 15 pin female
 RS-232                         RAN
 Sync Modem                  "IN" Port
  RxD   3 -----------------  6   RxD
  RxC  17 -----------------  9   RxC
  TxD   2 -----------------  1   TxD
  SG    7 ----------------- 12   Gnd
  Gnd   1 ----------------- Shell Gnd  (Solder to 15 pin connector shell
  Tie 4, 6, 20 Together.
  Leave 5 CTS unconnected.


                     Appendix C: UDS DDS/MR56 Setup

Instructions based on customer input.

The UDS Digital Data Set (DDS) has Table 4-1 on page 4-3 of the manual
with user selectable aptions.  Set them this way on both ends:

       Option          Value            Explanation
       ---------       ---------        ------------------------------

       TIMING          DDS              DDS-provided timing

       AUTBD OPT       DIS              Autobaud Option DISabled

       SYN/ASYNC       SYNC             Synchronous Operation

       RTS CONT        PERMANENT        Peg RTS high in the DDS. 

       BUFF OPT        OFF              (Motorola: Elastic buffer used
                                        to buffer externally-clocked
                                        transmitted data.  Normally used
                                        with a crossover cable in a tail
                                        circuit application) Don't use!!

       LB OPT          BIL LB EN        Bi-Lateral Loop Back ENabled
                       RMT LB EN        Remote LB Enabled

       DSR OPT         DSR ON           Peg DSR high in DDS

       SS OPT          SS OFF           System Status (Motorola: 'turn off')

       CA OPT          CA OFF           Circuit Assurance ( ' turn off')

       NET STAT        NS/OS            (Set per Motorola)

       RS-CS DLY       NORMAL           RTS/CTS delay

       DTE TESTS       DIS              DISABLE them all!!!!


                  Appendix D: Paradyne Model 3600 Settings:

Using standard NE/NF cables, I could get 1 RAN, or 2 RAN's to work at
57.6 KB, but 3 or 4 RAN's did not work in my lab.  These have worked
better with the High Performance cables, but there are still some 
problems with 56 KB lines.

For 1 remote RAN, the SMIT setting was:
     Line 1, 8 wire, 57.6 KB (56 KB set on modem),
     rs232_modem,  rs232_modem,  direct,  direct.

MODEM Settings:
Started by reloading settings from stored profiles in the modems.  These
profiles were called 'FacC' (Controller) on the local modem, and 'FacT'
(Tributary) on the remote modem. These modem has many settings to change,
and I only changed settings under DSU, GEN, and PrtSp.
 DSU Settings:  (Not all of these changed)
  56 KB, TxClkSource: int, Msg Clamp: enab, TxElasStor: disab
 TxelasStore: disab, 19.2 P: +6V, 64K Scramble: Off, 64 Latch..:on,
 AggrSw: disab, AgSw Time: Aggr, V.54: Disab,

GEN Settings:  (Not all of these changed from defaults)
 DDTE Port: EIA 232, RTS Cntrl: FrcOn, CTS Cntrl: Std, AntiSt: Disab,
  LSD Lead: Std, CTS Lead: Std, DSR FrcOn: Enab, SystemStat: Enab,
  DSR on Test: Enab, Cir Ass: Disab, Tst Patt: Std, RespondRDL: Enab,
  LL by DTE: Disab\< RL by DTE: Disab, Bilat..: Disab, Extern L: RATE,
  CCN by EL: Disab, DTR Alarm: Disab, 3.2 SW Vers: No,

PrtSp DSU Settings:
  Prt1: 56,

MUX Options Prt1:
  Async-Sync: Disab, Async Rate:=Sync, 8, 1, RTS Cntrl: FrcOn
  TxCarrSel: Const, RxCarrSel: Const, PCC BUffer: Disab, Elas
  Store: Disab, RTS/CTS Del: 0, DTR Alar: Disab, AntiStreaming: Disab,
  DSR FrcOn: Enab, DSR on Tst: Enab, Extend Chan: No, Upstrm Port: Prt1,

Mode:  DPII
              Appendix E: Customer suggestions for UDS 9600A/B

It may be possible that a cable that provides DSR support like the 
cable for the 5822 would work just fine.  Solution works as follows:  
Use standard NE/NF cables.  First modem provides clocking.  Set first
modem to 'Test Digital', and remote modem to 'Test Receive' and 
lestablished communications.  Now at exactly the time switched both 
modems to 'Normal' mode.  The 'test' mode forced DSR on, and established
a loopback test.  Remote RAN came to AC about one minute after switching 
both modems to 'Normal'.  9600 baud, 8 users and 1 printer gave 
good response.

             Appendix F: Multi-Tech MultiModemII DSU/CSU settings

Customer had these settings with analog line with converter.

   Option                     Setting
   DTR                        Forced ON
   MODE                       SDLC
   Command Response           Disabled
   AS/400 Mode                OFF
   RTS                        Forced On
   Remote digital loopback    OFF
   Leased-Line Operation      ON
   Synchronous Operation      ON
   Slave Clocking             OFF for local,   ON for remote
   Clocking:                  Internal for local, External for remote.
For digital leased line
   Clocking:                  External for both DSU/CSU's.

                 Appendix G: Synchronous link debugging.

When bringing up a remote sync link, multiple failures are possible.  By
setting up a remote link debugging setup, the diffecrent components can
be tested.  This proceedure is also applicable to EIA-422 Sync modem.
(just replace with appropriate cables i.e. NE - NG, and NF - NH
 and adjust smit configuration appropiately.)

| L E G E N D                                                          |
| EQUIPMENT                         CABLES/LINE                        | 
|  HA - host Adapter                 NC    - 8 wire direct cable       | 
|  LR - local RAN                    NE    - EIA232 local modem cable  | 
|  LM - local modem (CSU/DSU)        NF    - EIA232 remote modem cable | 
|  RM - remote modem (CSU/DSU)       T     - 128Port terminator        | 
|  RR - remote RAN                   telco - telephone co. line        | 

 DEBUG setup
 HA --NC-- LR --NE-- LM --telco-- RM --NF-- RR -T

 NODE setting on RAN; LR set to node 1, RR set to node 2.

 DEBUG setup smit configuration
 Node 1 Comm Mode   [direct]
 Node 2 Comm Mode   [232_modem]
 Node 3 Comm Mode   [232_modem]
 Node 4 Comm Mode   [direct]

 If all cables, lines, terminator and quipement are working then both
 RAN (local and remote) will come up to AC.

 Assumption: 128Port adapter is configured (i.e. cxma\# available)
 This guarantees that all components are working.

 If neither RAN comes to AC then the fun part begins.

 HA --NC-- LR --NE-- LM --telco-- RM --NF-- RR -T
                     \^3           \^2        \^1

 There are three places that can be looped back, that will help
 isolate the problem.  Locations 1, and 2, are remote loopback.
 When LR (local RAN) comes to 'AC' when in loopback. then the
 communication on the link to the point of loopback is good.
 (i.e. components to the point of loopback are functional)

 The 3 loopback points gives us a superior tool for Problem
 Determination (PD).  For example if LR comes to AC when in
 loopback at 2 and does not come to AC when in loopback at 1
 It shows problem in the NF component.  It is now time to
 explore why NF is failing: It may fail for one or more
 reasons listed below.
 1) RM (remote modem not configured to talk EIA-232)
 2) Cable NF sub-standard, bad cable
 3) RR power supply bad.
 4) T (terminator) missing from RR
 5) etc...

 Loop back
 1) We can isolate the remote RAN by turning it off.  When the Remote
    RAN is off the signals are looped back (i.e. TxD to RxD and TxC to RxC).
 2) Remote Loop back on RM
 3) DTE Loop back on LM
           Appendix H:  Modified NH/NG Cables for X.21 Modems

One customer reported the following Cable setup worked for connecting
RANs with X.21 modems from Telkom.

 Cable Used:
 Belden Spec Cable, 4 twisted pairs.
 Blue/Red, Yellow/Green, Black/White, Purple/Brown.
 The colours are given to indicated the relationship of pairs.

 Modified NH Cable:
         X.21 Modem Male                         RAN Female
         Pin     Signal          Colour          Signal  Pin
         ---     ------          ------          ------  ---
         11      RxDB            Purple          RxD-    6
         4       RxDA            Brown           RxD+    7
         9       TxDB            Black           TxD-    1
         2       TxDA            White           TxD+    2
         13      SigTimB         Green           TxC-    4 --+
                                        Loop at RAN end      |
                                                 RxC-    9 --+
         6       SigTimA         Yellow          TxC+    5 --+
                                        Loop at Ran end      |
                                                 RxC+   10 --+
         1       shield          Shield          shield  12
 Modified NG Cable:
         128 Port Male                           X.21 Modem Male
         Pin     Signal          Colour          Signal  Pin
         ---     ------          ------          ------  ---
         1       RxD-            Purple          RxDB    11
         2       RxD+            Brown           RxDA    4
  +--    4       RxC-            Green           SigTimB 13
  +--    9       TxC-
  +--    5       RxC+            Yellow          SigTimA 6
  +--    10      TxC+
         6       TxD-            Black           TxDB    9
         7       TxD+            White           TxDA    2
         12      shield          Shield          shield  1

 Customer made the changes that I had mailed him.  He is still having
 the same results (local comes to ac if the remote is turned off, and
 goes to p2 if the remote one is on.  The remote ran always stays at
 p1).  However now if he gets the local one to ac with the remote
 one turned off, and he runs cfgmgr, it will configure the ran, where
 as before it wasn't.
 Customer faxed cabling specs to motorola to see how our cabling matched
 with theirs.  He iss waiting on a callback.

 The customer has talked with Motorola and they don't see any problem
 with the cabling.  Motorola agreed that the timing signal should be
 coming from the line if it is a true dds line.  The modems should
 be able to handle that if that is true.  The customer is going to
 persue further this problem.  He is going to get a definite answer
 from the phone company.  He may also try getting some cables from
 Blackbox to try.  If this fails he will try the Mux eliminators from
 Inter Systems.  Customer will callback after he has done these things.

 Customer called back in and stated that his new cable works fine.
 The customer faxed me the cable pinouts that he used:

Local cable:
  Connecting the 128port controller to the local MR64 (Motorola UDS MR64

 HD-15(male)                DB-25 (male)
 128-port adapter
 or RAN out/T port          MR64 port
 - 1 ------------------------- 3 -
 + 2 ------------------------- 16 +

 - 4  ------------------------ 17 -
 + 5  ------------------------ 19 +

 - 6  ------------------------ 2 -
 + 7  ------------------------ 14 +

 - 9 ------------------------- 15 -
 +10 ------------------------- 13 +

  12 ------------------------- 7

 Connecting the remote MR64 to the remote RAN:

  DB=25(male)                  HD-15(female)
  MR64 port                    RAN IN port

   - 3  ----------------------- 6 -
   + 16 ----------------------- 7 +
   - 17 ----------------------- 9 -
   + 19 ----------------------- 10 +
    - 2  ----------------------- 1 -
   + 14 ----------------------- 2 +

   - 15 ----------------------- 4 -
   + 13 ----------------------- 5 +

      7 ----------------------- 12

 Customer has smit set to rs232_modem 57.6kbps and the modems in v.35
 mode with DDS timing.
 This cable works good at 56kbps with the setting in appendix C of the
 128port fax included above:

                     Appendix C: UDS DDS/MR56 Setup

Instructions based on customer input.

The UDS Digital Data Set (DDS) has Table 4-1 on page 4-3 of the manual
with user selectable aptions.  Set them this way on both ends:

       Option          Value            Explanation
       ---------       ---------        ------------------------------

       TIMING          DDS              DDS-provided timing

       AUTBD OPT       DIS              Autobaud Option DISabled

       SYN/ASYNC       SYNC             Synchronous Operation

       RTS CONT        PERMANENT        Peg RTS high in the DDS. 

       BUFF OPT        OFF              (Motorola: Elastic buffer used
                                        to buffer externally-clocked
                                        transmitted data.  Normally used
                                        with a crossover cable in a tail
                                        circuit application) Don't use!!

       LB OPT          BIL LB EN        Bi-Lateral Loop Back ENabled
                       RMT LB EN        Remote LB Enabled

       DSR OPT         DSR ON           Peg DSR high in DDS

       SS OPT          SS OFF           System Status (Motorola: 'turn off')

       CA OPT          CA OFF           Circuit Assurance ( ' turn off')

       NET STAT        NS/OS            (Set per Motorola)

       RS-CS DLY       NORMAL           RTS/CTS delay

       DTE TESTS       DIS              DISABLE them all!!!!

Support Line: Remote RAN for 128-port using Motorola DSU/CSU stuck at P1 ITEM: BO6608L
Dated: November 1996 Category: N/A
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