Mike's PBX Cookbook

D-Channel Daughterboard

The NTBK51 daughterboard provides two Multipurpose Serial Data Link (MSDL) based Downloadable D-channel (DCH) interfaces.

Example:

NTBK50 2Mb PRI, with
NTBK51 D-Channel daughter Board, and
NTAK20 Clock controller daughter Board

When the Dual D-Channel daughter Board is used with a NT5D97 Dual-port DTI2/PRI2 card (large system), the PRI cards DIP switches must set the MSDL device address. When used with a NTBK50 2.0 Mb PRI card (small system), only Port 1 is used. Refer to the Circuit Card Reference NTP for details.

NTBK51 Programming:

After building a DCH in LD 17, the configuration must always be written to the daughter board in LD 96: ENL MSDL X FDL

LD 17, CHG ADAN:

ADAN DCH x
CTYP MSDL         Card type is MSDL
DNUM xx           Use the DNUM that was set by the DIP switches
PORT 0            0 for EVEN PRI loop / 1 for ODD PRI loop, or small system
DES E1_DID        Designator
USR PRI
DCHL XX           Associated PRI Loop number
OTBF 32
PARM RS422 DTE
DRAT 64KC
CLOK EXT
IFC D100
SIDE USR
CNEG 1
RLS ID 25
RCAP 
MBGA NO
OVLR NO
OVLS NO
T200 3
T203 10
N200 3
N201 260
K 7

MSDL/DCH Maintenance:

Useful LD 96 MSDL/DCH maintenance commands. x is the MSDL device number (DNUM in LD 17), or DCH number.
When you first enable a new MSDL/DCH (or after a change) always 'Force Download' (FDL) the configuration, and watch for the dots.


ENL MSDL x (FDL, ALL)Enable MSDL device (FDL: Force DownLoad new or changed configuration)
DIS MSDL x (ALL)Disable MSDL device
RST MSDL xReset MSDL device
STAT MSDL (x) (FULL)Get MSDL status
SLFT MSDL xExecute a self-test on MSDL device x

ENL DCH x (FDL)Enable DCH x and attempt to establish the link, and force download to MSDL
DIS DCH xDisable DCH x
RST DCH xReset D-channel x, inhibit signaling
STAT DCH (x)Get status of one or all D-channels
MAP DCHShow the D-channel hardware port assignments

ENL AUTO xEnable automatic recovery for DCH x
DIS AUTO xDisable automatic recovery for DCH x

D Channel status:

D Channel status is displayed in LD 96 with STAT DCH x.
If x is omitted, the status of all D channels is output. The output format is:

DCH x : <Application_status> <Link_status> AUTO XX DES

Where:

Application status:
APRI - Awaiting PRI response
CPRI - Checking PRI
DIAG - application has failed
DSBL - application is disabled
OPER - link is operational
RST - application is in reset state
SDCH - Setting D-channel
Link status:
AEST - Awaiting establishment
ARLS - Awaiting release
EST ACTV - DCH link is established and active
EST STBY - DCH link is established and is the standby
FAIL - DCH link has failed
REST - request establishment
RLS - DCH link is released
RST - DCH link is in reset state
TST - Test mode

AUTO - if auto-recovery is enabled, AUTO is shown
XX - BKUP x / PRIM x (associated primary or backup DCH, only if applicable)
DES : - the DCH circuit designator follows

For example:

>ld 96
DCH000
.stat dch
DCH 05 : DSBL  RST         AUTO  DES : E1_DID   <- this is down!
DCH 06 : OPER  EST   ACTV  AUTO  DES : E1_TIE   <- this is good!

LED status:

PRI cards have faceplate status LEDs, the dual-color DCHI LED indicates the NTBK51 daughter board status:

StatusDefinition
Solid Red LEDNTBK51 is equipped, but disabled.
Solid Green LEDNTBK51 is enabled, but not necessarily established.
LED OffNTBK51 is not equipped.
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