Channel, SDLC - SDLC Status   (MM->1->3->8)

     Port 1 (SDLC) Message Status    
  0-  0   1-   0   3-   0   9-   0
 10-  0  11-   0  12-   0  13-   0
 20-  0  21-   0  22-   0  23-   0
 24-  0  25-   0  26-   0  27-   0
 30-  0  40-   0
 No response-  0 Frame- 0
      Header-  0 Status-00
 Rx Buf Length  0

The TS2 specification (section 3.3.1.4) defines the command frames shown in this table (0, 1, 3, 9, 10, etc.) which are initiated by the controller to all enabled BIU devices.  The TS2 specification also defines the response frame (or messages) returned by the BIU's over the SDLC port. (shown as "0" values in this table).  

SDLC status information is primarily a development tools, but it can be usefull diagnosing some problems relating to the Type 1 TS2 cabinet facility.  However, for most situations, SDLC problems can be identified quickly from the controller status screen ( [Alt] 9 or MM->7->9->5).