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.

Command	Description
ENL MSDL x (FDL, ALL)	Enable MSDL device (FDL: Force DownLoad new or changed configuration)
DIS MSDL x (ALL)	Disable MSDL device
RST MSDL x	Reset MSDL device
STAT MSDL (x) (FULL)	Get MSDL status
SLFT MSDL x	Execute 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 x	Disable DCH x
RST DCH x	Reset D-channel x, inhibit signaling
STAT DCH (x)	Get status of one or all D-channels
MAP DCH	Show the D-channel hardware port assignments

ENL AUTO x	Enable automatic recovery for DCH x
DIS AUTO x	Disable 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 in 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

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:

Status Definition

NTBK51 is equipped, but disabled.

NTBK51 is enabled, but not necessarily established.

NTBK51 is not equipped.

Status	Definition
	NTBK51 is equipped, but disabled.
	NTBK51 is enabled, but not necessarily established.
	NTBK51 is not equipped.